update ucx dav-2 tip

Fri, 19 Dec 2025 17:53:18 +0100

author
Olaf Wintermann <olaf.wintermann@gmail.com>
date
Fri, 19 Dec 2025 17:53:18 +0100
branch
dav-2
changeset 891
4d58cbcc9efa
parent 890
e77ccf1c4bb3

update ucx

dav/config.c file | annotate | diff | comparison | revisions
dav/db.c file | annotate | diff | comparison | revisions
dav/finfo.c file | annotate | diff | comparison | revisions
dav/main.c file | annotate | diff | comparison | revisions
dav/scfg.c file | annotate | diff | comparison | revisions
dav/sync.c file | annotate | diff | comparison | revisions
dav/system.c file | annotate | diff | comparison | revisions
dav/tags.c file | annotate | diff | comparison | revisions
libidav/config.c file | annotate | diff | comparison | revisions
libidav/crypto.c file | annotate | diff | comparison | revisions
libidav/davqlexec.c file | annotate | diff | comparison | revisions
libidav/davqlparser.c file | annotate | diff | comparison | revisions
libidav/methods.c file | annotate | diff | comparison | revisions
libidav/pwdstore.c file | annotate | diff | comparison | revisions
libidav/resource.c file | annotate | diff | comparison | revisions
libidav/session.c file | annotate | diff | comparison | revisions
libidav/utils.c file | annotate | diff | comparison | revisions
libidav/versioning.c file | annotate | diff | comparison | revisions
libidav/webdav.c file | annotate | diff | comparison | revisions
libidav/xml.c file | annotate | diff | comparison | revisions
make/gcc.mk file | annotate | diff | comparison | revisions
test/crypto.c file | annotate | diff | comparison | revisions
test/main.c file | annotate | diff | comparison | revisions
ucx/allocator.c file | annotate | diff | comparison | revisions
ucx/array_list.c file | annotate | diff | comparison | revisions
ucx/buffer.c file | annotate | diff | comparison | revisions
ucx/compare.c file | annotate | diff | comparison | revisions
ucx/cx/allocator.h file | annotate | diff | comparison | revisions
ucx/cx/array_list.h file | annotate | diff | comparison | revisions
ucx/cx/buffer.h file | annotate | diff | comparison | revisions
ucx/cx/collection.h file | annotate | diff | comparison | revisions
ucx/cx/common.h file | annotate | diff | comparison | revisions
ucx/cx/compare.h file | annotate | diff | comparison | revisions
ucx/cx/hash_map.h file | annotate | diff | comparison | revisions
ucx/cx/iterator.h file | annotate | diff | comparison | revisions
ucx/cx/json.h file | annotate | diff | comparison | revisions
ucx/cx/kv_list.h file | annotate | diff | comparison | revisions
ucx/cx/linked_list.h file | annotate | diff | comparison | revisions
ucx/cx/list.h file | annotate | diff | comparison | revisions
ucx/cx/map.h file | annotate | diff | comparison | revisions
ucx/cx/properties.h file | annotate | diff | comparison | revisions
ucx/cx/string.h file | annotate | diff | comparison | revisions
ucx/cx/tree.h file | annotate | diff | comparison | revisions
ucx/hash_map.c file | annotate | diff | comparison | revisions
ucx/iterator.c file | annotate | diff | comparison | revisions
ucx/json.c file | annotate | diff | comparison | revisions
ucx/kv_list.c file | annotate | diff | comparison | revisions
ucx/linked_list.c file | annotate | diff | comparison | revisions
ucx/list.c file | annotate | diff | comparison | revisions
ucx/map.c file | annotate | diff | comparison | revisions
ucx/printf.c file | annotate | diff | comparison | revisions
ucx/properties.c file | annotate | diff | comparison | revisions
ucx/string.c file | annotate | diff | comparison | revisions
ucx/tree.c file | annotate | diff | comparison | revisions
--- a/dav/config.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/config.c	Fri Dec 19 17:53:18 2025 +0100
@@ -112,7 +112,7 @@
     }
     
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 1024, cxDefaultAllocator, CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, 1024, CX_BUFFER_AUTO_EXTEND);
     cx_stream_copy(file, &buf, (cx_read_func)fread, (cx_write_func)cxBufferWrite);
     fclose(file);
     
@@ -304,8 +304,9 @@
      * The list secrets->location contains urls or repo names as
      * location strings. We need a list, that contains only urls
      */
-    CxList *locations = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)cmp_url_cred_entry, CX_STORE_POINTERS);
-    cxDefineDestructor(locations, free_cred_location);
+    CxList *locations = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    cxSetCompareFunc(locations, (cx_compare_func)cmp_url_cred_entry);
+    cxSetDestructor(locations, free_cred_location);
     CxIterator i = cxListIterator(secrets->locations);
     cx_foreach(PwdIndexEntry*, e, i) {
         CxIterator entry_iter = cxListIterator(e->locations);
@@ -325,9 +326,9 @@
     // create full request url string and remove protocol prefix
     cxmutstr req_url_proto = util_concat_path_s(cx_strcast(repo->url.value), cx_str(path));
     cxstring req_url = cx_strcast(req_url_proto);
-    if(cx_strprefix(req_url, CX_STR("http://"))) {
+    if(cx_strprefix(req_url, cx_str("http://"))) {
         req_url = cx_strsubs(req_url, 7);
-    } else if(cx_strprefix(req_url, CX_STR("https://"))) {
+    } else if(cx_strprefix(req_url, cx_str("https://"))) {
         req_url = cx_strsubs(req_url, 8);
     }
     
@@ -340,9 +341,9 @@
         cxstring cred_url = cx_str(cred->location);
         
         // remove protocol prefix
-        if(cx_strprefix(cred_url, CX_STR("http://"))) {
+        if(cx_strprefix(cred_url, cx_str("http://"))) {
             cred_url = cx_strsubs(cred_url, 7);
-        } else if(cx_strprefix(cred_url, CX_STR("https://"))) {
+        } else if(cx_strprefix(cred_url, cx_str("https://"))) {
             cred_url = cx_strsubs(cred_url, 8);
         }
         
--- a/dav/db.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/db.c	Fri Dec 19 17:53:18 2025 +0100
@@ -58,8 +58,8 @@
     db->resources = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 2048);
     db->conflict = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
 
-    cxDefineDestructor(db->resources, local_resource_free);
-    cxDefineDestructor(db->conflict, local_resource_free);
+    cxSetDestructor(db->resources, local_resource_free);
+    cxSetDestructor(db->conflict, local_resource_free);
     
     xmlTextReaderPtr reader = xmlReaderForFile(db_file, NULL, 0);
     if(!reader) {
@@ -112,9 +112,7 @@
 }
 
 void process_parts(xmlTextReaderPtr reader, LocalResource *res) {
-    size_t parts_alloc = 32;
-    size_t parts_size = 0;
-    FilePart *parts = calloc(parts_alloc, sizeof(FilePart));
+    CX_ARRAY(FilePart, parts);
     
     FilePart *current_part = NULL;
     
@@ -128,10 +126,10 @@
         if(type == XML_READER_TYPE_ELEMENT) {
             if(depth == 3 && xstreq(name, "part")) {
                 FilePart newpart = { 0 };
-                cx_array_add(&parts, &parts_size, &parts_alloc, sizeof(FilePart), &newpart, cx_array_default_reallocator);
+                cx_array_add(parts, newpart);
                 
-                current_part = &parts[parts_size-1];
-                current_part->block = parts_size;
+                current_part = &parts.data[parts.size-1];
+                current_part->block = parts.size;
             } else if(depth == 4) {
                 if(xstreq(name, "hash")) {
                     field = 0;
@@ -164,14 +162,14 @@
     }
     
     if(!err) {
-        res->parts = parts;
-        res->numparts = parts_size;
+        res->parts = parts.data;
+        res->numparts = parts.size;
     } else {
-        for(int i=0;i<parts_size;i++) {
-            free(parts[i].etag);
-            free(parts[i].hash);
+        for(int i=0;i<parts.size;i++) {
+            free(parts.data[i].etag);
+            free(parts.data[i].hash);
         }
-        free(parts);
+        free(parts.data);
     }
 }
 
--- a/dav/finfo.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/finfo.c	Fri Dec 19 17:53:18 2025 +0100
@@ -50,22 +50,22 @@
 uint32_t parse_finfo_settings(const char *str, char **error) {
     cxstring s = cx_str(str);
     
-    if(!cx_strcmp(s, CX_STR("*")) || !cx_strcmp(s, CX_STR("a")) || !cx_strcmp(s, CX_STR("all"))) {
+    if(!cx_strcmp(s, cx_str("*")) || !cx_strcmp(s, cx_str("a")) || !cx_strcmp(s, cx_str("all"))) {
         return FINFO_MTIME|FINFO_OWNER|FINFO_MODE|FINFO_XATTR;
     } 
     
-    CxStrtokCtx fs = cx_strtok(s, CX_STR(","), INT_MAX);
+    CxStrtokCtx fs = cx_strtok(s, cx_str(","), INT_MAX);
     cxstring f;
     uint32_t finfo = 0;
     char *err = NULL;
     while(cx_strtok_next(&fs, &f)) {
-        if(!cx_strcasecmp(f, CX_STR("mtime"))) {
+        if(!cx_strcasecmp(f, cx_str("mtime"))) {
             finfo |= FINFO_MTIME;
-        } else if(!cx_strcasecmp(f, CX_STR("owner"))) {
+        } else if(!cx_strcasecmp(f, cx_str("owner"))) {
             finfo |= FINFO_OWNER;
-        } else if(!cx_strcasecmp(f, CX_STR("mode"))) {
+        } else if(!cx_strcasecmp(f, cx_str("mode"))) {
             finfo |= FINFO_MODE;
-        } else if(!cx_strcasecmp(f, CX_STR("xattr"))) {
+        } else if(!cx_strcasecmp(f, cx_str("xattr"))) {
             finfo |= FINFO_XATTR;
         } else if(error && !err) {
             err = cx_strdup(f).ptr;
@@ -130,13 +130,6 @@
 }
 
 
-static void* array_realloc(void *array,
-            size_t capacity,
-            size_t elem_size,
-            struct cx_array_reallocator_s *alloc)
-{
-    return realloc(array, capacity * elem_size);
-}
 
 XAttributes* xml_get_attributes(DavXmlNode *xml) {
     XAttributes *attributes = calloc(1, sizeof(XAttributes));
@@ -161,16 +154,11 @@
                 char *xattr_name = dav_xml_get_attr(node, "name");
                 if(xattr_name) {                 
                     char *xname = strdup(xattr_name);
-                    cx_array_copy(
-                            (void**)&attributes->names,
-                            &x_names_size,
-                            &x_names_alloc,
-                            sizeof(size_t),
-                            count,
-                            &xname,
-                            sizeof(void*),
-                            1,
-                            cx_array_default_reallocator);
+                    if(x_names_size >= x_names_alloc) {
+                        x_names_alloc += 16;
+                        attributes->names = realloc(attributes->names, sizeof(char*) * x_names_alloc);
+                    }
+                    attributes->names[x_names_size++] = xname;
                     
                     char *text = dav_xml_getstring(node->children);
                     if(!text) {
@@ -184,16 +172,11 @@
                     value.ptr = val;
                     value.length = len;
                     
-                    cx_array_copy(
-                            (void**)&attributes->values,
-                            &x_values_size,
-                            &x_values_alloc,
-                            sizeof(size_t),
-                            count,
-                            &value,
-                            sizeof(cxmutstr),
-                            1,
-                            cx_array_default_reallocator);
+                    if(x_values_size >= x_values_alloc) {
+                        x_values_alloc += 16;
+                        attributes->values = realloc(attributes->values, sizeof(cxmutstr) * x_values_alloc);
+                    }
+                    attributes->values[x_values_size++] = value;
                     
                     count++;
                 }
--- a/dav/main.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/main.c	Fri Dec 19 17:53:18 2025 +0100
@@ -706,8 +706,8 @@
     }
     
     // get list of resources
-    CxList *reslist = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(reslist, free_getres);
+    CxList *reslist = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(reslist, free_getres);
     uint64_t totalsize = 0;
     uint64_t rescount = 0;
     
@@ -718,7 +718,7 @@
     char *structure = cmd_getoption(a, "structure");
     
     // iterate over resource tree
-    CxList *stack = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *stack = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     cxListInsert(stack, 0, getres);
     while(cxListSize(stack) > 0) {
         GetResource *g = cxListAt(stack, 0);
@@ -1721,7 +1721,7 @@
     
     //printf("header: %.*s\n", s*n, header);
     cxstring h = cx_strn(header, s*n);
-    if(cx_strprefix(h, CX_STR("Date:"))) {
+    if(cx_strprefix(h, cx_str("Date:"))) {
         cxstring v = cx_strsubs(h, 5);
         *date_str = cx_strdup(cx_strtrim(v)).ptr;
     }
@@ -1961,7 +1961,7 @@
     time_t timeout = 0;
     char *timeoutstr = cmd_getoption(a, "timeout");
     if(timeoutstr) {
-        if(!cx_strcasecmp(cx_str(timeoutstr), CX_STR("infinite"))) {
+        if(!cx_strcasecmp(cx_str(timeoutstr), cx_str("infinite"))) {
             timeout = -1;
         } else {
             uint64_t i;
@@ -1997,7 +1997,7 @@
 
 static char* read_line() {
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 128, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, 128, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     int c;
     while((c = getchar()) != EOF) {
         if(c == '\n') {
@@ -2345,7 +2345,7 @@
 
 char* stdin2str() {
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     size_t size = cx_stream_copy(stdin, &buf, (cx_read_func)fread, (cx_write_func)cxBufferWrite);
     if(size == 0) {
         cxBufferDestroy(&buf);
@@ -2393,7 +2393,7 @@
 
 char* xml2str(DavXmlNode *node) {
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 256, cxDefaultAllocator, CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, 256, CX_BUFFER_AUTO_EXTEND);
     xml2str_i(node, &buf, 0);
     cxBufferPut(&buf, 0);
     return buf.space;
@@ -2401,7 +2401,7 @@
 
 void printxmldoc(FILE *out, char *root, char *rootns, DavXmlNode *content) {
     CxMap *nsmap = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
-    cxDefineDestructor(nsmap, free);
+    cxSetDestructor(nsmap, free);
     
     cxMapPut(nsmap, cx_hash_key_str(rootns), strdup("x0"));
     fprintf(out, "%s", "<?xml version=\"1.0\"?>\n");
@@ -2533,10 +2533,10 @@
         cxstring url = cx_strcast(repo->url.value);
         if(repo->user.value.ptr && !cmd_getoption(args, "plain")) {
             int hostindex = 0;
-            if(cx_strprefix(url, CX_STR("https://"))) {
+            if(cx_strprefix(url, cx_str("https://"))) {
                 printf("https://");
                 hostindex = 8;
-            } else if(cx_strprefix(url, CX_STR("http://"))) {
+            } else if(cx_strprefix(url, cx_str("http://"))) {
                 printf("http://");
                 hostindex = 7;
             }
@@ -2661,8 +2661,8 @@
     
     // optionally, get one or more locations
     char *location = NULL;
-    CxList *locations = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(locations, free);
+    CxList *locations = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(locations, free);
     while((location = assistant_getoptcfg("Location"))) {
         cxListAdd(locations, location);
     }
@@ -2968,13 +2968,13 @@
 
 static char** read_args_from_stdin(int *argc) {
     // read stdin into buffer
-    CxBuffer *in = cxBufferCreate(NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *in = cxBufferCreate(cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cx_stream_copy(stdin, in, (cx_read_func)fread, (cx_write_func)cxBufferWrite);
     
     // split input into lines
     size_t count = 0;
     cxmutstr *lines; 
-    count = cx_strsplit_ma(cxDefaultAllocator, cx_mutstrn(in->space, in->pos), CX_STR("\n"), INT_MAX, &lines);
+    count = cx_strsplit_ma(cxDefaultAllocator, cx_mutstrn(in->space, in->pos), cx_str("\n"), INT_MAX, &lines);
     
     char **args = NULL;
     if(count > 0) {
@@ -3172,7 +3172,7 @@
         char *lspath = NULL;
         if(path[plen-1] == '/') {
             lspath = strdup(path);
-            filter = CX_STR("");
+            filter = cx_str("");
         } else {
             lspath = util_parent_path(path);
             filter = cx_str(util_resource_name(path));
@@ -3191,7 +3191,7 @@
                     }
                 }
                 
-                CxBuffer *out = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+                CxBuffer *out = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
                 cxBufferWrite(repo->name.value.ptr, repo->name.value.length, 1, out);
                 if(space) {
                     size_t l = strlen(elm->path);
--- a/dav/scfg.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/scfg.c	Fri Dec 19 17:53:18 2025 +0100
@@ -164,12 +164,12 @@
 }
 
 Filter* parse_filter(xmlNode *node) {
-    CxList *include = cxLinkedListCreate(cxDefaultAllocator, NULL, sizeof(regex_t));
-    CxList *exclude = cxLinkedListCreate(cxDefaultAllocator, NULL, sizeof(regex_t));
-    CxList *tags = cxLinkedListCreate(cxDefaultAllocator, NULL, CX_STORE_POINTERS);
+    CxList *include = cxLinkedListCreate(cxDefaultAllocator, sizeof(regex_t));
+    CxList *exclude = cxLinkedListCreate(cxDefaultAllocator, sizeof(regex_t));
+    CxList *tags = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
     
-    cxDefineDestructor(include, regfree);
-    cxDefineDestructor(exclude, regfree);
+    cxSetDestructor(include, regfree);
+    cxSetDestructor(exclude, regfree);
     // TODO: set tags destructor
     
     if(scfg_load_filter(node, include, exclude, tags)) {
@@ -347,7 +347,7 @@
 }
 
 static CxList* parse_splitconfig(xmlNode *node, int *error) {
-    CxList *splitconfig = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *splitconfig = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     int err = 0;
     xmlNode *c = node->children;
     while(c) {
@@ -431,9 +431,9 @@
     char *logfile = NULL;
     TagConfig *tagconfig = NULL;
     Versioning *versioning = NULL;
-    CxList *include = cxLinkedListCreateSimple(sizeof(regex_t));
-    CxList *exclude = cxLinkedListCreateSimple(sizeof(regex_t));
-    CxList *tagfilter = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *include = cxLinkedListCreate(NULL, sizeof(regex_t));
+    CxList *exclude = cxLinkedListCreate(NULL, sizeof(regex_t));
+    CxList *tagfilter = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     CxList *splitconfig = NULL;
     int max_retry = 0;
     int allow_cmd = SYNC_CMD_PULL | SYNC_CMD_PUSH
--- a/dav/sync.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/sync.c	Fri Dec 19 17:53:18 2025 +0100
@@ -684,7 +684,7 @@
 }
 
 void res2map(DavResource *root, CxMap *map) {
-    CxList *stack = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *stack = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     cxListInsert(stack, 0, root->children);
     while(cxListSize(stack) > 0) {
         DavResource *res = cxListAt(stack, 0);
@@ -837,20 +837,20 @@
     int sync_error = 0;
     int sync_conflict = 0;
     
-    CxList *res_modified = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    CxList *res_new = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    CxList *res_moved = cxLinkedListCreateSimple(CX_STORE_POINTERS); // type: MovedFile*
-    CxList *res_link = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    CxList *res_conflict = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    CxList *res_mkdir = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    CxList *res_metadata = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    CxList *res_broken = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *res_modified = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    CxList *res_new = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    CxList *res_moved = cxLinkedListCreate(NULL, CX_STORE_POINTERS); // type: MovedFile*
+    CxList *res_link = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    CxList *res_conflict = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    CxList *res_mkdir = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    CxList *res_metadata = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    CxList *res_broken = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     CxMap  *lres_removed = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16); // type: LocalResource*
     
     //UcxMap *svrres = ucx_map_new(db->resources->count);
     CxMap *dbres = mapClone(cxDefaultAllocator, db->resources, NULL, NULL);
     
-    CxList *stack = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *stack = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     cxListInsert(stack, 0, ls->children);
     while(cxListSize(stack) > 0) {
         DavResource *res = cxListAt(stack, 0);
@@ -1100,7 +1100,8 @@
         }
     }
     
-    CxList *rmdirs = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_pathlen_cmp, CX_STORE_POINTERS);
+    CxList *rmdirs = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    cxSetCompareFunc(rmdirs, (cx_compare_func)resource_pathlen_cmp);
     mi = cxMapIteratorValues(lres_removed);
     cx_foreach(LocalResource *, removed_res, mi) {
         if(sync_shutdown) {
@@ -1252,7 +1253,7 @@
             }
         } else if(local->etag) {
             cxstring e = cx_str(etag);
-            if(cx_strprefix(e, CX_STR("W/"))) {
+            if(cx_strprefix(e, cx_str("W/"))) {
                 e = cx_strsubs(e, 2);
             }
             if(!strcmp(e.ptr, local->etag)) {
@@ -1429,8 +1430,8 @@
         int64_t *truncate_file,
         int *err)
 {
-    CxList *updates = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(updates, filepart_free);
+    CxList *updates = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(updates, filepart_free);
     
     size_t local_numparts = local ? local->numparts : 0;
     fseeko(out, 0, SEEK_END);
@@ -1438,7 +1439,7 @@
     
     int error = 0;
     
-    CxBuffer *buf = cxBufferCreate(NULL, blocksize, cxDefaultAllocator, 0);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, blocksize, 0);
     
     int64_t maxsize = -1;
     
@@ -2175,15 +2176,23 @@
     int sync_conflict = 0;
     int sync_error = 0;
     
-    CxList *ls_new = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_modified = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_conflict = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_update = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_delete = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_move = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_copy = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    CxList *ls_mkcol = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)resource_path_cmp, CX_STORE_POINTERS);
-    
+    CxList *ls_new = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_modified = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_conflict = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_update = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_delete = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_move = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_copy = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *ls_mkcol = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    
+    cxSetCompareFunc(ls_new, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_modified, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_conflict, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_update, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_delete, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_move, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_copy, (cx_compare_func)resource_path_cmp);
+    cxSetCompareFunc(ls_mkcol, (cx_compare_func)resource_path_cmp);
       
     // upload all changed files
     //UcxList *resources = cmd_getoption(a, "read") ?
@@ -2297,7 +2306,7 @@
     
     // find all deleted files and cleanup the database
     CxMapIterator mapIter = cxMapIterator(db->resources);
-    CxList *removed_res = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *removed_res = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     cx_foreach(CxMapEntry *, entry, mapIter) { 
         LocalResource *local = entry->value;
         // all filtered files should be removed from the database
@@ -2579,7 +2588,8 @@
     // delete all removed files
     cxListSort(ls_delete);
     
-    CxList *cols = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)localres_cmp_path_desc, CX_STORE_POINTERS);
+    CxList *cols = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    cxSetCompareFunc(cols, (cx_compare_func)localres_cmp_path_desc);
     CxList *cols_del = cols; // remember pointer for cleanup
     CxList *col_list = cols;
     CxList *deletelist = ls_delete;
@@ -2734,8 +2744,10 @@
     }
     remove_deleted_conflicts(dir, db);
     
-    CxList *modified = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)localres_cmp_path, CX_STORE_POINTERS);
-    CxList *deleted = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)localres_cmp_path, CX_STORE_POINTERS);
+    CxList *modified = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    CxList *deleted = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    cxSetCompareFunc(modified, (cx_compare_func)localres_cmp_path);
+    cxSetCompareFunc(deleted, (cx_compare_func)localres_cmp_path);
     
     // iterate over all db resources and check if any resource is
     // modified or deleted
@@ -3039,10 +3051,10 @@
 }
 
 CxList* local_scan(SyncDirectory *dir, SyncDatabase *db) {
-    CxList *resources = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *resources = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     
     char *path = strdup("/");
-    CxList *stack = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *stack = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     cxListInsert(stack, 0, path);
     while(cxListSize(stack) > 0) {
         // get a directory path from the stack and read all entries
@@ -3429,7 +3441,7 @@
             ret = 1;
         } else if(etag) {
             cxstring e = cx_str(etag);
-            if(cx_strprefix(e, CX_STR("W/"))) {
+            if(cx_strprefix(e, cx_str("W/"))) {
                 e = cx_strsubs(e, 2);
             }
             if(strcmp(e.ptr, res->etag)) {
@@ -3467,7 +3479,7 @@
     }
     
     cxstring e = cx_str(etag);
-    if(cx_strprefix(e, CX_STR("W/"))) {
+    if(cx_strprefix(e, cx_str("W/"))) {
         e = cx_strsubs(e, 2);
     }
     local->etag = cx_strdup(e).ptr;
@@ -3878,7 +3890,7 @@
         free(local_path);
         
         if(tag_length > 0) {
-            buf = cxBufferCreate(tag_data, (size_t)tag_length, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS);
+            buf = cxBufferCreate(cxDefaultAllocator, tag_data, (size_t)tag_length, CX_BUFFER_FREE_CONTENTS);
             buf->size = (size_t)tag_length;
         }
     }
@@ -4204,7 +4216,7 @@
     }
     
     CxMap *updated_parts_map = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, (nblocks/2)+64);
-    cxDefineDestructor(updated_parts_map, filepart_free);
+    cxSetDestructor(updated_parts_map, filepart_free);
     
     int blockindex = 0;
     int uploaded_parts = 0;
@@ -4287,7 +4299,7 @@
     
     // get etags from uploaded resources
     // also delete everything, that is not part of the file
-    CxList *updated_parts = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *updated_parts = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     DavResource *parts = dav_query(res->session, "select D:getetag from %s order by name", res->path);
     if(!parts) {
         log_resource_error(res->session, parts->path);
@@ -5032,9 +5044,8 @@
     CxMapIterator mi = cxMapIteratorValues(db->conflict);
     CxList* conflict_sources = cxLinkedListCreate(
             cxDefaultAllocator,
-            (cx_compare_func) strcmp,
-            CX_STORE_POINTERS
-    );
+            CX_STORE_POINTERS);
+    cxSetCompareFunc(conflict_sources, (cx_compare_func)strcmp);
     cx_foreach(LocalResource *, res, mi) {
         cxListAdd(conflict_sources, res->conflict_source);
     }
@@ -5148,7 +5159,8 @@
             }
             
             DavResource *child = vcol->children;
-            CxList *children = cxLinkedListCreate(cxDefaultAllocator, (cx_compare_func)strcmp, CX_STORE_POINTERS);
+            CxList *children = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+            cxSetCompareFunc(children, (cx_compare_func)strcmp);
             while(child) {
                 cxListAdd(children, child);
                 child = child->next;
@@ -5396,7 +5408,7 @@
                 newtag->name = tag;
                 newtag->color = tagcolor;
                 if(!tags) {
-                    tags = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+                    tags = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
                 }
                 cxListAdd(tags, newtag);
                 store_tags = TRUE;
@@ -5677,7 +5689,7 @@
 int cmd_check_repositories(CmdArgs *a) {
     int ret = EXIT_SUCCESS;
 
-    CxList *reponames = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *reponames = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     {
         CxMapIterator iter = scfg_directory_iterator();
         cx_foreach(SyncDirectory *, dir, iter) {
--- a/dav/system.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/system.c	Fri Dec 19 17:53:18 2025 +0100
@@ -339,7 +339,7 @@
     int ret = 0;
     
     cxstring path_s = cx_str(path);
-    if(cx_strsuffix(path_s, CX_STR(".lnk"))) {
+    if(cx_strsuffix(path_s, cx_str(".lnk"))) {
         // looks like a .lnk file
         // check content
         IShellLink *sl;
--- a/dav/tags.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/dav/tags.c	Fri Dec 19 17:53:18 2025 +0100
@@ -71,8 +71,8 @@
 }
 
 CxList* parse_text_taglist(const char *buf, size_t length) {
-    CxList *tags = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(tags, free_dav_tag);
+    CxList *tags = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(tags, free_dav_tag);
     
     int line_start = 0;
     for(int i=0;i<length;i++) {
@@ -126,7 +126,7 @@
         return NULL;
     }
     
-    CxBuffer *buf = cxBufferCreate(NULL, 128, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 128, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     CxIterator i = cxListIterator(tags);
     cx_foreach(DavTag *, tag, i) {
         if(tag->color) {
@@ -140,11 +140,11 @@
 
 
 CxList* parse_csv_taglist(const char *buf, size_t length) {
-    CxList *taglist = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(taglist, free_dav_tag);
+    CxList *taglist = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(taglist, free_dav_tag);
     
     cxstring str = cx_strn(buf, length);
-    CxStrtokCtx tags = cx_strtok(str, CX_STR(","), INT_MAX);
+    CxStrtokCtx tags = cx_strtok(str, cx_str(","), INT_MAX);
     cxstring tagstr;
     while(cx_strtok_next(&tags, &tagstr)) {
         cxstring trimmed_tag = cx_strtrim(tagstr);
@@ -159,7 +159,7 @@
 }
 
 CxBuffer* create_csv_taglist(CxList *tags) {
-    CxBuffer *buf = cxBufferCreate(NULL, 128, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 128, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     int insertsep = 0;
     CxIterator i = cxListIterator(tags);
     cx_foreach(DavTag*, tag, i) {
@@ -205,8 +205,8 @@
 } 
 
 CxList* parse_dav_xml_taglist(DavXmlNode *taglistnode) {
-    CxList *tags = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(tags, free_dav_tag);
+    CxList *tags = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(tags, free_dav_tag);
     
     DavXmlNode *node = taglistnode;
     while(node) {
@@ -287,7 +287,7 @@
 }
 
 CxList* parse_macos_taglist(const char *buf, size_t length) {
-    CxList *taglist = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *taglist = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     taglist->collection.simple_destructor = (cx_destructor_func)free_dav_tag;
     
     CFDataRef data = CFDataCreateWithBytesNoCopy(
@@ -330,7 +330,7 @@
     cx_foreach(DavTag*, tag, iter) {
         CFStringRef str = NULL;
         if(tag->color) {
-            cxmutstr s = cx_strcat(3, cx_mutstr(tag->name), CX_STR("\n"), cx_str(tag->color));
+            cxmutstr s = cx_strcat(3, cx_mutstr(tag->name), cx_str("\n"), cx_str(tag->color));
             str = CFStringCreateWithCString(kCFAllocatorDefault, s.ptr, kCFStringEncodingUTF8);
             free(s.ptr);
         } else {
@@ -417,8 +417,8 @@
     // this map is used to check the existence of tags
     CxMap *tag_map = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 32);
     // merged taglist
-    CxList *new_tags = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(new_tags, free_dav_tag);
+    CxList *new_tags = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(new_tags, free_dav_tag);
 
     // add all local tags
     if(tags1) {
--- a/libidav/config.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/config.c	Fri Dec 19 17:53:18 2025 +0100
@@ -285,7 +285,7 @@
         return NULL;
     }
     
-    CxBuffer *buf = cxBufferCreate(NULL, textLen, cxDefaultAllocator, CX_BUFFER_AUTO_EXTEND|CX_BUFFER_FREE_CONTENTS);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, textLen, CX_BUFFER_AUTO_EXTEND|CX_BUFFER_FREE_CONTENTS);
     cxBufferWrite(xmlText, 1, textLen, buf);
     xmlFree(xmlText);
     return buf;
@@ -940,9 +940,9 @@
     path->length = 0;
     
     int s;
-    if(cx_strprefix(url, CX_STR("http://"))) {
+    if(cx_strprefix(url, cx_str("http://"))) {
         s = 7;
-    } else if(cx_strprefix(url, CX_STR("https://"))) {
+    } else if(cx_strprefix(url, cx_str("https://"))) {
         s = 8;
     } else {
         s = 1;
@@ -963,10 +963,10 @@
         // TODO: who is responsible for freeing this repository?
         // how can the callee know, if he has to call free()?
         repo = dav_repository_new(config);
-        repo->name.value = cx_strdup_a(config->mp->allocator, CX_STR(""));
+        repo->name.value = cx_strdup_a(config->mp->allocator, cx_str(""));
         if(url.ptr[url.length-1] == '/') {
             repo->url.value = cx_strdup_a(config->mp->allocator, url);
-            *path = cx_strdup(CX_STR("/"));
+            *path = cx_strdup(cx_str("/"));
         } else if (cx_strchr(url, '/').length > 0) {
             // TODO: fix the following workaround after
             //       fixing the inconsistent behavior of util_url_*()
@@ -975,7 +975,7 @@
             *path = cx_strdup(util_url_path_s(url));
         } else {
             repo->url.value = cx_strdup(url);
-            *path = cx_strdup(CX_STR("/"));
+            *path = cx_strdup(cx_str("/"));
         }
     }
     
--- a/libidav/crypto.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/crypto.c	Fri Dec 19 17:53:18 2025 +0100
@@ -1522,7 +1522,7 @@
 }
 
 CxBuffer* aes_encrypt_buffer(CxBuffer *in, DavKey *key) {
-    CxBuffer *encbuf = cxBufferCreate(NULL, in->size, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *encbuf = cxBufferCreate(cxDefaultAllocator, NULL, in->size, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     if(!encbuf) {
         return NULL;
     }
@@ -1549,7 +1549,7 @@
 }
 
 CxBuffer* aes_decrypt_buffer(CxBuffer *in, DavKey *key) {
-    CxBuffer *decbuf = cxBufferCreate(NULL, in->size, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *decbuf = cxBufferCreate(cxDefaultAllocator, NULL, in->size, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     if(!decbuf) {
         return NULL;
     }
--- a/libidav/davqlexec.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/davqlexec.c	Fri Dec 19 17:53:18 2025 +0100
@@ -179,7 +179,7 @@
 
 cxmutstr dav_format_string(const CxAllocator *a, cxstring fstr, DavQLArgList *ap, davqlerror_t *error) {
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 128, a, CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, a, NULL, 128, CX_BUFFER_AUTO_EXTEND);
     
     int placeholder = 0;
     for(int i=0;i<fstr.length;i++) {
@@ -285,11 +285,11 @@
     
     CxIterator i = cxListIterator(fields);
     cx_foreach(DavQLField*, field, i) {
-        if(!cx_strcmp(field->name, CX_STR("*"))) {
+        if(!cx_strcmp(field->name, cx_str("*"))) {
             cxMapFree(properties);
             *isallprop = 1;
             return create_allprop_propfind_request();
-        } else if(!cx_strcmp(field->name, CX_STR("-"))) {
+        } else if(!cx_strcmp(field->name, cx_str("-"))) {
             cxMapFree(properties);
             return create_propfind_request(sn, NULL, "propfind", 0);
         } else {
@@ -302,7 +302,7 @@
     }
     
     CxMapIterator mi = cxMapIteratorValues(properties);
-    CxList *list = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    CxList *list = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     cx_foreach(DavProperty*, value, mi) {
         cxListAdd(list, value);
     }
@@ -483,11 +483,11 @@
     cxMempoolRegister(mp, rqbuf, (cx_destructor_func)cxBufferFree);
     
     // compile field list
-    CxList *cfieldlist = cxLinkedListCreate(mp->allocator, NULL, CX_STORE_POINTERS);
+    CxList *cfieldlist = cxLinkedListCreate(mp->allocator, CX_STORE_POINTERS);
     if(st->fields) {
         CxIterator i = cxListIterator(st->fields);
         cx_foreach(DavQLField*, field, i) {
-            if(cx_strcmp(field->name, CX_STR("*")) && cx_strcmp(field->name, CX_STR("-"))) {
+            if(cx_strcmp(field->name, cx_str("*")) && cx_strcmp(field->name, cx_str("-"))) {
                 // compile field expression
                 CxBuffer *code = dav_compile_expr(
                         sn->context,
@@ -543,7 +543,7 @@
     // compile order criterion
     CxList *ordercr = NULL;
     if(st->orderby) {
-        ordercr = cxLinkedListCreate(mp->allocator, NULL, sizeof(DavOrderCriterion));
+        ordercr = cxLinkedListCreate(mp->allocator, sizeof(DavOrderCriterion));
         CxIterator i = cxListIterator(st->orderby);
         cx_foreach(DavQLOrderCriterion*, oc, i) {
             DavQLExpression *column = oc->column;
@@ -601,7 +601,7 @@
     
     DavResource *selroot = dav_resource_new(sn, path.ptr);
     
-    CxList *stack = cxLinkedListCreateSimple(sizeof(DavQLRes));
+    CxList *stack = cxLinkedListCreate(NULL, sizeof(DavQLRes));
     // initialize the stack with the requested resource
     DavQLRes res;
     res.resource = selroot;
@@ -609,7 +609,7 @@
     cxListInsert(stack, 0, &res);
     
     // reuseable response buffer
-    CxBuffer *rpbuf = cxBufferCreate(NULL, 4096, mp->allocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *rpbuf = cxBufferCreate(mp->allocator, NULL, 4096, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     if(!rpbuf) {
         // TODO: cleanup
         cxMempoolFree(mp);
@@ -750,21 +750,21 @@
 }
 
 int dav_identifier2resprop(cxstring src, davqlresprop_t *prop) {
-    if(!cx_strcmp(src, CX_STR("name"))) {
+    if(!cx_strcmp(src, cx_str("name"))) {
         *prop = DAVQL_RES_NAME;
-    } else if(!cx_strcmp(src, CX_STR("path"))) {
+    } else if(!cx_strcmp(src, cx_str("path"))) {
         *prop = DAVQL_RES_PATH;
-    } else if(!cx_strcmp(src, CX_STR("href"))) {
+    } else if(!cx_strcmp(src, cx_str("href"))) {
         *prop = DAVQL_RES_HREF;
-    } else if(!cx_strcmp(src, CX_STR("contentlength"))) {
+    } else if(!cx_strcmp(src, cx_str("contentlength"))) {
         *prop = DAVQL_RES_CONTENTLENGTH;
-    } else if(!cx_strcmp(src, CX_STR("contenttype"))) {
+    } else if(!cx_strcmp(src, cx_str("contenttype"))) {
         *prop = DAVQL_RES_CONTENTTYPE;
-    } else if(!cx_strcmp(src, CX_STR("creationdate"))) {
+    } else if(!cx_strcmp(src, cx_str("creationdate"))) {
         *prop = DAVQL_RES_CREATIONDATE;
-    } else if(!cx_strcmp(src, CX_STR("lastmodified"))) {
+    } else if(!cx_strcmp(src, cx_str("lastmodified"))) {
         *prop = DAVQL_RES_LASTMODIFIED;
-    } else if(!cx_strcmp(src, CX_STR("iscollection"))) {
+    } else if(!cx_strcmp(src, cx_str("iscollection"))) {
         *prop = DAVQL_RES_ISCOLLECTION;
     } else {
         return 0;
@@ -835,10 +835,10 @@
                     return -1;
                 }
             } else if(!dav_identifier2resprop(src, &cmd.data.resprop)) {
-                if(!cx_strcmp(src, CX_STR("true"))) {
+                if(!cx_strcmp(src, cx_str("true"))) {
                     cmd.type = DAVQL_CMD_INT;
                     cmd.data.integer = 1;
-                } else if(!cx_strcmp(src, CX_STR("false"))) {
+                } else if(!cx_strcmp(src, cx_str("false"))) {
                     cmd.type = DAVQL_CMD_INT;
                     cmd.data.integer = 0;
                 } else {
@@ -1032,7 +1032,7 @@
 }
 
 CxBuffer* dav_compile_expr(DavContext *ctx, const CxAllocator *a, DavQLExpression *lexpr, DavQLArgList  *ap) {
-    CxBuffer *bcode = cxBufferCreate(NULL, 512, a, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *bcode = cxBufferCreate(a, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     if(!bcode) {
         return NULL;
     }
--- a/libidav/davqlparser.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/davqlparser.c	Fri Dec 19 17:53:18 2025 +0100
@@ -169,7 +169,7 @@
 
 static void dav_debug_ql_expr_print(DavQLExpression *expr) {
     if (dav_debug_ql_expr_selected(expr)) {
-        cxstring empty = CX_STR("(empty)");
+        cxstring empty = cx_str("(empty)");
         printf(
             "Text: %.*s\nType: %s\nOperator: %s\n",
             sfmtarg(expr->srctext),
@@ -422,7 +422,7 @@
     
     // we try to achieve two things: get as many information as possible
     // and recover the concrete source string (and not the token strings)
-    cxstring emptystring = CX_STR("");
+    cxstring emptystring = cx_str("");
     cxstring prev = token->prev ? (token->prev->prev ?
         token_sstr(token->prev->prev) : token_sstr(token->prev))
         : emptystring;
@@ -457,10 +457,10 @@
 static const char *special_token_symbols = ",()+-*/&|^~=!<>";
 
 static _Bool iskeyword(DavQLToken *token) {
-    cxstring keywords[] ={CX_STR("select"), CX_STR("set"), CX_STR("from"), CX_STR("at"), CX_STR("as"),
-        CX_STR("where"), CX_STR("anywhere"), CX_STR("like"), CX_STR("unlike"), CX_STR("and"),
-        CX_STR("or"), CX_STR("not"), CX_STR("xor"), CX_STR("with"), CX_STR("infinity"),
-        CX_STR("order"), CX_STR("by"), CX_STR("asc"), CX_STR("desc")
+    cxstring keywords[] ={cx_str("select"), cx_str("set"), cx_str("from"), cx_str("at"), cx_str("as"),
+        cx_str("where"), cx_str("anywhere"), cx_str("like"), cx_str("unlike"), cx_str("and"),
+        cx_str("or"), cx_str("not"), cx_str("xor"), cx_str("with"), cx_str("infinity"),
+        cx_str("order"), cx_str("by"), cx_str("asc"), cx_str("desc")
     };
     for (int i = 0 ; i < sizeof(keywords)/sizeof(cxstring) ; i++) {
         if (!cx_strcasecmp(token->value, keywords[i])) {
@@ -471,8 +471,8 @@
 }
 
 static _Bool islongoperator(DavQLToken *token) {
-    cxstring operators[] = {CX_STR("and"), CX_STR("or"), CX_STR("not"), CX_STR("xor"),
-        CX_STR("like"), CX_STR("unlike")
+    cxstring operators[] = {cx_str("and"), cx_str("or"), cx_str("not"), cx_str("xor"),
+        cx_str("like"), cx_str("unlike")
     };
     for (int i = 0 ; i < sizeof(operators)/sizeof(cxstring) ; i++) {
         if (!cx_strcasecmp(token->value, operators[i])) {
@@ -484,7 +484,7 @@
 
 static int dav_stmt_add_field(DavQLStatement *stmt, DavQLField *field) {
     if(!stmt->fields) {
-        stmt->fields = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+        stmt->fields = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
         if(!stmt->fields) {
             stmt->errorcode = DAVQL_ERROR_OUT_OF_MEMORY;
             return 1;
@@ -645,7 +645,7 @@
     
     alloc_token();
     token->tokenclass = DAVQL_TOKEN_END;
-    token->value = CX_STR("");
+    token->value = cx_str("");
     
     cx_linked_list_add((void**)&tokens_begin, (void**)&tokens_end, offsetof(DavQLToken, prev), offsetof(DavQLToken, next), token);
     return tokens_begin;
@@ -745,7 +745,7 @@
 
 static void fmt_args_add(DavQLStatement *stmt, void *data) {
     if(!stmt->args) {
-        stmt->args = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+        stmt->args = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     }
     cxListAdd(stmt->args, data);
 }
@@ -1508,7 +1508,7 @@
     DavQLOrderCriterion crit;
     
     if(!stmt->orderby) {
-        stmt->orderby = cxLinkedListCreateSimple(sizeof(DavQLOrderCriterion));
+        stmt->orderby = cxLinkedListCreate(NULL, sizeof(DavQLOrderCriterion));
         if(!stmt->orderby) {
             return 0;
         }
@@ -1837,7 +1837,7 @@
 
 void dav_free_statement(DavQLStatement *stmt) {
     if(stmt->fields) {
-        cxDefineDestructor(stmt->fields, dav_free_field);
+        cxSetDestructor(stmt->fields, dav_free_field);
         cxListFree(stmt->fields);
     }
     
@@ -1849,7 +1849,7 @@
     }
     
     if(stmt->orderby) {
-        cxDefineDestructor(stmt->orderby, dav_free_order_criterion);
+        cxSetDestructor(stmt->orderby, dav_free_order_criterion);
         cxListFree(stmt->orderby);
     }
     if(stmt->args) {
--- a/libidav/methods.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/methods.c	Fri Dec 19 17:53:18 2025 +0100
@@ -74,7 +74,7 @@
     curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, cxBufferWrite);
     curl_easy_setopt(handle, CURLOPT_WRITEDATA, response);
     CxMap *respheaders = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 32);
-    cxDefineDestructor(respheaders, free);
+    cxSetDestructor(respheaders, free);
     util_capture_header(handle, respheaders);
     
     for(int i=0;i<maxretry;i++) {
@@ -122,39 +122,39 @@
 }
 
 CxBuffer* create_allprop_propfind_request(void) {
-    CxBuffer *buf = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:propfind xmlns:D=\"DAV:\">\n");
+    s = cx_str("<D:propfind xmlns:D=\"DAV:\">\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:allprop/></D:propfind>\n");
+    s = cx_str("<D:allprop/></D:propfind>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     return buf;
 }
 
 CxBuffer* create_cryptoprop_propfind_request(void) {
-    CxBuffer *buf = cxBufferCreate(NULL, 256, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 256, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:propfind xmlns:D=\"DAV:\" xmlns:idav=\"" DAV_NS "\">\n");
+    s = cx_str("<D:propfind xmlns:D=\"DAV:\" xmlns:idav=\"" DAV_NS "\">\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:prop><idav:crypto-prop/></D:prop></D:propfind>\n");
+    s = cx_str("<D:prop><idav:crypto-prop/></D:prop></D:propfind>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     return buf;
 }
 
 CxBuffer* create_propfind_request(DavSession *sn, CxList *properties, char *rootelm, DavBool nocrypt) {
-    CxBuffer *buf = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
     int add_crypto_name = 1;
@@ -193,7 +193,7 @@
         cxMapPut(namespaces, cx_hash_key_str("idav"), &idav_ns);
     }
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // write root element and namespaces
@@ -201,31 +201,31 @@
     
     CxMapIterator mapi = cxMapIteratorValues(namespaces);
     cx_foreach(DavNamespace*, ns, mapi) {
-        s = CX_STR(" xmlns:");
+        s = cx_str(" xmlns:");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         s = cx_str(ns->prefix);
         cxBufferWrite(s.ptr, 1, s.length, buf);
-        s = CX_STR("=\"");
+        s = cx_str("=\"");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         s = cx_str(ns->name);
         cxBufferWrite(s.ptr, 1, s.length, buf);
-        s = CX_STR("\"");
+        s = cx_str("\"");
         cxBufferWrite(s.ptr, 1, s.length, buf);
     }
-    s = CX_STR(">\n");
+    s = cx_str(">\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // default properties
-    s = CX_STR("<D:prop>\n");
+    s = cx_str("<D:prop>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:creationdate />\n<D:getlastmodified />\n");
+    s = cx_str("<D:creationdate />\n<D:getlastmodified />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:getcontentlength />\n<D:getcontenttype />\n");
+    s = cx_str("<D:getcontentlength />\n<D:getcontenttype />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:resourcetype />\n");
+    s = cx_str("<D:resourcetype />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // crypto properties
@@ -233,19 +233,19 @@
         if(add_crypto_name) {
             cxBufferPut(buf, '<');
             cxBufferPutString(buf, crypto_ns);
-            s = CX_STR(":crypto-name />\n");
+            s = cx_str(":crypto-name />\n");
             cxBufferWrite(s.ptr, 1, s.length, buf);
         }
         if(add_crypto_key) {
             cxBufferPut(buf, '<');
             cxBufferPutString(buf, crypto_ns);
-            s = CX_STR(":crypto-key />\n");
+            s = cx_str(":crypto-key />\n");
             cxBufferWrite(s.ptr, 1, s.length, buf);
         }
         if(add_crypto_hash) {
             cxBufferPut(buf, '<');
             cxBufferPutString(buf, crypto_ns);
-            s = CX_STR(":crypto-hash />\n");
+            s = cx_str(":crypto-hash />\n");
             cxBufferWrite(s.ptr, 1, s.length, buf);
         }
     }
@@ -254,15 +254,15 @@
     if(properties) {
         CxIterator i = cxListIterator(properties);
         cx_foreach(DavProperty*, prop, i) {
-            s = CX_STR("<");
+            s = cx_str("<");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(prop->ns->prefix);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(":");
+            s = cx_str(":");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(prop->name);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(" />\n");
+            s = cx_str(" />\n");
             cxBufferWrite(s.ptr, 1, s.length, buf);
         }
     }
@@ -275,35 +275,35 @@
 }
 
 CxBuffer* create_basic_propfind_request(void) {
-    CxBuffer *buf = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:propfind xmlns:D=\"DAV:\" xmlns:i=\"");
+    s = cx_str("<D:propfind xmlns:D=\"DAV:\" xmlns:i=\"");
     cxBufferWrite(s.ptr, 1, s.length, buf);  
-    s = CX_STR(DAV_NS);
+    s = cx_str(DAV_NS);
     cxBufferWrite(s.ptr, 1, s.length, buf);
-    s = CX_STR("\" >\n");
+    s = cx_str("\" >\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // properties
-    s = CX_STR("<D:prop>\n");
+    s = cx_str("<D:prop>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
-    s = CX_STR("<D:resourcetype />\n");
+    s = cx_str("<D:resourcetype />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
-    s = CX_STR("<i:crypto-key />\n");
+    s = cx_str("<i:crypto-key />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
-    s = CX_STR("<i:crypto-name />\n");
+    s = cx_str("<i:crypto-name />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
-    s = CX_STR("<i:crypto-hash />\n");
+    s = cx_str("<i:crypto-hash />\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
-    s = CX_STR("</D:prop>\n");
+    s = cx_str("</D:prop>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // end
-    s = CX_STR("</D:propfind>\n");
+    s = cx_str("</D:propfind>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     return buf;
@@ -356,7 +356,7 @@
     char *crypto_name = NULL; // name set by crypto-name property
     char *crypto_key = NULL;
     
-    result->properties = cxLinkedListCreateSimple(CX_STORE_POINTERS); // xmlNode list
+    result->properties = cxLinkedListCreate(NULL, CX_STORE_POINTERS); // xmlNode list
     
     xmlNode *node = parser->current->children;
     while(node) {
@@ -389,7 +389,7 @@
                                 return -1;
                             }
                             status_str = cx_strsubsl(status_str, 9, 3);
-                            if(!cx_strcmp(status_str, CX_STR("200"))) {
+                            if(!cx_strcmp(status_str, cx_str("200"))) {
                                 ok = 1;
                             }
                         }
@@ -590,7 +590,7 @@
     //DavResource *res = resource;
     DavResource *res = NULL;
     const char *href = NULL;
-    CxList *properties = cxLinkedListCreateSimple(CX_STORE_POINTERS); // xmlNode list
+    CxList *properties = cxLinkedListCreate(NULL, CX_STORE_POINTERS); // xmlNode list
     char *crypto_name = NULL; // name set by crypto-name property
     char *crypto_key = NULL;
     
@@ -639,7 +639,7 @@
                                 return 1;
                             }
                             status_str = cx_strsubsl(status_str, 9, 3);
-                            if(!cx_strcmp(status_str, CX_STR("200"))) {
+                            if(!cx_strcmp(status_str, cx_str("200"))) {
                                 ok = 1;
                             }
                         }
@@ -822,11 +822,11 @@
 }
 
 CxBuffer* create_proppatch_request(DavResourceData *data) {
-    CxBuffer *buf = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
     CxMap *namespaces = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 8);
-    cxDefineDestructor(namespaces, free);
+    cxSetDestructor(namespaces, free);
 
     {
         char prefix[8];
@@ -851,30 +851,30 @@
         }
     }
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // write root element and namespaces
-    s = CX_STR("<D:propertyupdate xmlns:D=\"DAV:\"");
+    s = cx_str("<D:propertyupdate xmlns:D=\"DAV:\"");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     CxMapIterator mapi = cxMapIterator(namespaces);
     cx_foreach(CxMapEntry*, entry, mapi) {
-        s = CX_STR(" xmlns:");
+        s = cx_str(" xmlns:");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         s = cx_str(entry->value);
         cxBufferWrite(s.ptr, 1, s.length, buf);
-        s = CX_STR("=\"");
+        s = cx_str("=\"");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         s = cx_strn(entry->key->data, entry->key->len);
         cxBufferWrite(s.ptr, 1, s.length, buf);
-        s = CX_STR("\"");
+        s = cx_str("\"");
         cxBufferWrite(s.ptr, 1, s.length, buf);
     }
-    s = CX_STR(">\n");
+    s = cx_str(">\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     if(data->set) {
-        s = CX_STR("<D:set>\n<D:prop>\n");
+        s = cx_str("<D:set>\n<D:prop>\n");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         CxIterator i = cxListIterator(data->set);
         cx_foreach(DavProperty*, property, i) {
@@ -884,15 +884,15 @@
             }
             
             // begin tag
-            s = CX_STR("<");
+            s = cx_str("<");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(prefix);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(":");
+            s = cx_str(":");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(property->name);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(">");
+            s = cx_str(">");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             
             // content
@@ -904,43 +904,43 @@
             }
             
             // end tag
-            s = CX_STR("</");
+            s = cx_str("</");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(prefix);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(":");
+            s = cx_str(":");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(property->name);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(">\n");
+            s = cx_str(">\n");
             cxBufferWrite(s.ptr, 1, s.length, buf);
         }
-        s = CX_STR("</D:prop>\n</D:set>\n");
+        s = cx_str("</D:prop>\n</D:set>\n");
         cxBufferWrite(s.ptr, 1, s.length, buf);
     }
     if(data->remove) {
-        s = CX_STR("<D:remove>\n<D:prop>\n");
+        s = cx_str("<D:remove>\n<D:prop>\n");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         CxIterator i = cxListIterator(data->remove);
         cx_foreach(DavProperty*, property, i) {
             char *prefix = cxMapGet(namespaces, cx_hash_key_str(property->ns->name));
             
-            s = CX_STR("<");
+            s = cx_str("<");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(prefix);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(":");
+            s = cx_str(":");
             cxBufferWrite(s.ptr, 1, s.length, buf);
             s = cx_str(property->name);
             cxBufferWrite(s.ptr, 1, s.length, buf);
-            s = CX_STR(" />\n");
+            s = cx_str(" />\n");
             cxBufferWrite(s.ptr, 1, s.length, buf);
         }
-        s = CX_STR("</D:prop>\n</D:remove>\n");
+        s = cx_str("</D:prop>\n</D:remove>\n");
         cxBufferWrite(s.ptr, 1, s.length, buf);
     }
     
-    s = CX_STR("</D:propertyupdate>\n");
+    s = cx_str("</D:propertyupdate>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     // cleanup namespace map
@@ -950,43 +950,43 @@
 }
 
 CxBuffer* create_crypto_proppatch_request(DavSession *sn, DavKey *key, const char *name, const char *hash) {
-    CxBuffer *buf = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:propertyupdate xmlns:D=\"DAV:\" xmlns:idav=\"" DAV_NS "\">\n");
+    s = cx_str("<D:propertyupdate xmlns:D=\"DAV:\" xmlns:idav=\"" DAV_NS "\">\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:set>\n<D:prop>\n");
+    s = cx_str("<D:set>\n<D:prop>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     if(DAV_ENCRYPT_NAME(sn)) {
-        s = CX_STR("<idav:crypto-name>");
+        s = cx_str("<idav:crypto-name>");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         char *crname = aes_encrypt(name, strlen(name), key);
         cxBufferPutString(buf, crname);
         free(crname);
-        s = CX_STR("</idav:crypto-name>\n");
+        s = cx_str("</idav:crypto-name>\n");
         cxBufferWrite(s.ptr, 1, s.length, buf);
     }
     
-    s = CX_STR("<idav:crypto-key>");
+    s = cx_str("<idav:crypto-key>");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     cxBufferPutString(buf, key->name);
-    s = CX_STR("</idav:crypto-key>\n");
+    s = cx_str("</idav:crypto-key>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     if(hash) {
-        s = CX_STR("<idav:crypto-hash>");
+        s = cx_str("<idav:crypto-hash>");
         cxBufferWrite(s.ptr, 1, s.length, buf);
         cxBufferPutString(buf, hash);
-        s = CX_STR("</idav:crypto-hash>\n");
+        s = cx_str("</idav:crypto-hash>\n");
         cxBufferWrite(s.ptr, 1, s.length, buf);
     }
     
-    s = CX_STR("</D:prop>\n</D:set>\n</D:propertyupdate>\n");
+    s = cx_str("</D:prop>\n</D:set>\n</D:propertyupdate>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     return buf;
@@ -1025,7 +1025,7 @@
     
     CxBuffer *buf = NULL;
     if(!read_func) {
-        buf = cxBufferCreate(data, length, cxDefaultAllocator, 0);
+        buf = cxBufferCreate(cxDefaultAllocator, data, length, 0);
         buf->size = length;
         data = buf;
         read_func = (dav_read_func)cxBufferRead;
@@ -1148,7 +1148,7 @@
         free(ltheader);
     }
     //cxstring deststr = ucx_sprintf("Destination: %s", dest);
-    cxmutstr deststr = cx_strcat(2, CX_STR("Destination: "), cx_str(dest));
+    cxmutstr deststr = cx_strcat(2, cx_str("Destination: "), cx_str(dest));
     headers = curl_slist_append(headers, deststr.ptr);
     if(override) {
         headers = curl_slist_append(headers, "Overwrite: T");
@@ -1167,19 +1167,19 @@
 
 
 CxBuffer* create_lock_request(void) {
-    CxBuffer *buf = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cxstring s;
     
-    s = CX_STR("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
+    s = cx_str("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("<D:lockinfo xmlns:D=\"DAV:\">\n"
+    s = cx_str("<D:lockinfo xmlns:D=\"DAV:\">\n"
           "<D:lockscope><D:exclusive/></D:lockscope>\n"
           "<D:locktype><D:write/></D:locktype>\n"
           "<D:owner><D:href>http://davutils.org/libidav/</D:href></D:owner>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
-    s = CX_STR("</D:lockinfo>\n");
+    s = cx_str("</D:lockinfo>\n");
     cxBufferWrite(s.ptr, 1, s.length, buf);
     
     return buf;
--- a/libidav/pwdstore.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/pwdstore.c	Fri Dec 19 17:53:18 2025 +0100
@@ -64,7 +64,7 @@
         return NULL;
     }
     
-    CxBuffer *buf = cxBufferCreate(NULL, 2048, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *buf = cxBufferCreate(cxDefaultAllocator, NULL, 2048, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     cx_stream_copy(in, buf, (cx_read_func)fread, (cx_write_func)cxBufferWrite);
     fclose(in);
     
@@ -75,8 +75,8 @@
     
     PwdStore *p = malloc(sizeof(PwdStore));
     p->ids = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
-    p->locations = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    p->noloc = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    p->locations = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    p->noloc = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     p->index = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
     p->content = buf;
     p->key = NULL;
@@ -96,10 +96,10 @@
 PwdStore* pwdstore_new(void) {
     PwdStore *p = calloc(1, sizeof(PwdStore));
     p->ids = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
-    p->locations = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    p->noloc = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    p->locations = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    p->noloc = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     p->index = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
-    p->content = cxBufferCreate(NULL, PWDS_HEADER_SIZE, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    p->content = cxBufferCreate(cxDefaultAllocator, NULL, PWDS_HEADER_SIZE, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     PWDS_MAGIC(p) = PWDS_MAGIC_CHAR;
     PWDS_VERSION(p) = 1;
     PWDS_ENC(p) = DAV_KEY_AES256;
@@ -128,8 +128,8 @@
     
     PwdStore *newp = calloc(1, sizeof(PwdStore));
     newp->ids = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
-    newp->locations = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    newp->noloc = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+    newp->locations = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    newp->noloc = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
     newp->index = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
     newp->content = newbuffer;
     newp->key = key;
@@ -149,7 +149,7 @@
         PwdIndexEntry *entry = e->value;
         CxList *locations = NULL;
         if(entry->locations) {
-            locations = cxLinkedListCreateSimple(CX_STORE_POINTERS);
+            locations = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
             CxIterator li = cxListIterator(entry->locations);
             cx_foreach(char *, location, li) {
                 cxListAdd(locations, strdup(location));
@@ -206,8 +206,8 @@
     }
       
     char *id = NULL;
-    CxList *locations = cxLinkedListCreateSimple(CX_STORE_POINTERS);
-    cxDefineDestructor(locations, free);
+    CxList *locations = cxLinkedListCreate(NULL, CX_STORE_POINTERS);
+    cxSetDestructor(locations, free);
     
     // get id (required)
     int ret = 0;
@@ -330,7 +330,7 @@
     s->encoffset = PWDS_HEADER_SIZE + indexlen;
     
     // the index starts after the header
-    CxBuffer *index = cxBufferCreate(s->content->space+PWDS_HEADER_SIZE, indexlen, cxDefaultAllocator, 0);
+    CxBuffer *index = cxBufferCreate(cxDefaultAllocator, s->content->space+PWDS_HEADER_SIZE, indexlen, 0);
     index->size = indexlen;
     
     // read index
@@ -352,7 +352,7 @@
     
     // decrypt contet
     size_t encsz = p->content->size - p->encoffset;
-    CxBuffer *enc = cxBufferCreate(p->content->space + p->encoffset, encsz, cxDefaultAllocator, 0);
+    CxBuffer *enc = cxBufferCreate(cxDefaultAllocator, p->content->space + p->encoffset, encsz, 0);
     enc->size = encsz;
     enc->size = p->content->size - p->encoffset;
     CxBuffer *content = aes_decrypt_buffer(enc, p->key);
@@ -398,7 +398,7 @@
 }
 
 void pwdstore_free(PwdStore* p) {
-    cxDefineDestructor(p->ids, pwdstore_free_entry);
+    cxSetDestructor(p->ids, pwdstore_free_entry);
     cxMapFree(p->ids);
     
     cxListFree(p->locations);
@@ -477,8 +477,8 @@
         return 1;
     }
     
-    CxBuffer *index = cxBufferCreate(NULL, 2048, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
-    CxBuffer *content = cxBufferCreate(NULL, 2048, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *index = cxBufferCreate(cxDefaultAllocator, NULL, 2048, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *content = cxBufferCreate(cxDefaultAllocator, NULL, 2048, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     // create index
     CxIterator i = cxListIterator(p->noloc);
@@ -547,7 +547,7 @@
     
     char *ps_password = NULL;
     if(secrets->unlock_cmd && strlen(secrets->unlock_cmd) > 0) {
-        CxBuffer *cmd_out = cxBufferCreate(NULL, 128, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+        CxBuffer *cmd_out = cxBufferCreate(cxDefaultAllocator, NULL, 128, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
         if(!util_exec_command(secrets->unlock_cmd, cmd_out)) {
             // command successful, get first line from output without newline
             // and use that as password for the secretstore
--- a/libidav/resource.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/resource.c	Fri Dec 19 17:53:18 2025 +0100
@@ -360,7 +360,7 @@
     cxstring ns_str = cx_str(ns);
     cxstring name_str = cx_str(name);
     
-    return cx_strcat_a(a, 4, ns_str, CX_STR("\0"), name_str, CX_STR("\0"));
+    return cx_strcat_a(a, 4, ns_str, cx_str("\0"), name_str, cx_str("\0"));
 }
 
 
@@ -619,7 +619,7 @@
 
 static int add2propertylist(const CxAllocator *a, CxList **list, DavProperty *property) {
     if(!*list) {
-        CxList *newlist = cxLinkedListCreate(a, NULL, CX_STORE_POINTERS);
+        CxList *newlist = cxLinkedListCreate(a, CX_STORE_POINTERS);
         if(!newlist) {
             return 1;
         }
@@ -788,7 +788,7 @@
     CxMempool *mp = cxMempoolCreateSimple(64);
     const CxAllocator *a = mp->allocator;
     
-    CxList *proplist = cxArrayListCreate(a, NULL, sizeof(DavProperty), numprop);
+    CxList *proplist = cxArrayListCreate(a, sizeof(DavProperty), numprop);
     for(size_t i=0;i<numprop;i++) {
         DavProperty p;
         p.name = properties[i].name;
@@ -870,7 +870,7 @@
                         data->read,
                         data->seek);
             } else {
-                buf = cxBufferCreate(data->content, data->length, cxDefaultAllocator, 0);
+                buf = cxBufferCreate(cxDefaultAllocator, data->content, data->length, 0);
                 buf->size = data->length;
                 enc = aes_encrypter_new(
                         sn->key,
@@ -912,7 +912,7 @@
             HashStream hstr;
             CxBuffer *iobuf = NULL;
             if(!data->read) {
-                iobuf = cxBufferCreate(data->content, data->length, cxDefaultAllocator, 0);
+                iobuf = cxBufferCreate(cxDefaultAllocator, data->content, data->length, 0);
                 iobuf->size = data->length;
                 init_hash_stream(
                         &hstr,
@@ -1045,7 +1045,7 @@
     sn->error = DAV_OK;
     if(data->set || data->remove > 0) {
         CxBuffer *request = create_proppatch_request(data);
-        CxBuffer *response = cxBufferCreate(NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+        CxBuffer *response = cxBufferCreate(cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
         //printf("request:\n%.*s\n\n", request->pos, request->space);
 
         CURLcode ret = do_proppatch_request(sn, locktoken, request, response);
@@ -1196,7 +1196,7 @@
     DavLock *lock = dav_get_lock(res->session, res->path);
     char *locktoken = lock ? lock->token : NULL;
     
-    CxBuffer *response = cxBufferCreate(NULL, 4096, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *response = cxBufferCreate(cxDefaultAllocator, NULL, 4096, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     CURLcode ret = do_delete_request(res->session, locktoken, response);
     long status = 0;
     curl_easy_getinfo (handle, CURLINFO_RESPONSE_CODE, &status);
@@ -1399,7 +1399,7 @@
     util_set_url(sn, dav_resource_get_href(res));
     
     CxBuffer *request = create_lock_request();
-    CxBuffer *response = cxBufferCreate(NULL, 512, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *response = cxBufferCreate(cxDefaultAllocator, NULL, 512, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     CURLcode ret = do_lock_request(sn, request, response, timeout);
     
     //printf("\nlock\n");
@@ -1476,7 +1476,7 @@
     }
     
     CxBuffer *request = create_crypto_proppatch_request(sn, sn->key, name, hash);
-    CxBuffer *response = cxBufferCreate(NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *response = cxBufferCreate(cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     util_set_url(sn, href);
     // TODO: lock
@@ -1503,11 +1503,11 @@
         return NULL;
     }
     
-    CxBuffer *content = cxBufferCreate(NULL, 2048, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *content = cxBufferCreate(cxDefaultAllocator, NULL, 2048, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     // create an xml document containing all properties
     CxMap *nsmap = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 8);
-    cxDefineDestructor(nsmap, free);
+    cxSetDestructor(nsmap, free);
     cxMapPut(nsmap, cx_hash_key_str("DAV:"), strdup("D"));
     
     cxBufferPutString(content, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
--- a/libidav/session.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/session.c	Fri Dec 19 17:53:18 2025 +0100
@@ -65,7 +65,7 @@
     sn->locks = NULL;
 
     // set proxy
-    DavProxy *proxy = cx_strprefix(url, CX_STR("https")) ? context->https_proxy
+    DavProxy *proxy = cx_strprefix(url, cx_str("https")) ? context->https_proxy
                                                   : context->http_proxy;
     
     if (proxy->url) {
@@ -395,8 +395,8 @@
         cxstring p = cx_str(path);
         CxBuffer href;
         CxBuffer pbuf;
-        cxBufferInit(&href, NULL, 256, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
-        cxBufferInit(&pbuf, NULL, 256, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+        cxBufferInit(&href, cxDefaultAllocator, NULL, 256, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+        cxBufferInit(&pbuf, cxDefaultAllocator, NULL, 256, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
         
         int start = 0;
         int begin = 0;
@@ -435,7 +435,7 @@
         CxBuffer *rqbuf = create_basic_propfind_request();
         
         cxstring remaining = cx_strsubs(p, start);
-        CxStrtokCtx elms = cx_strtok(remaining, CX_STR("/"), INT_MAX);
+        CxStrtokCtx elms = cx_strtok(remaining, cx_str("/"), INT_MAX);
         DavResource *res = root;
         cxBufferPutString(&pbuf, res->path);
         // iterate over all remaining path elements
@@ -568,7 +568,8 @@
     // create lock manager
     DavLockManager *locks = cxMalloc(sn->mp->allocator, sizeof(DavLockManager));
     locks->resource_locks = cxHashMapCreate(sn->mp->allocator, CX_STORE_POINTERS, 16);
-    locks->collection_locks = cxLinkedListCreate(sn->mp->allocator, dav_lock_cmp, CX_STORE_POINTERS);
+    locks->collection_locks = cxLinkedListCreate(sn->mp->allocator, CX_STORE_POINTERS);
+    cxSetCompareFunc(locks->collection_locks, dav_lock_cmp);
     sn->locks = locks;
     return 0;
 }
--- a/libidav/utils.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/utils.c	Fri Dec 19 17:53:18 2025 +0100
@@ -521,7 +521,7 @@
 char* util_path_normalize(const char *path) {
     size_t len = strlen(path);
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, len+1, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, len+1, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     if(path[0] == '/') {
         cxBufferPut(&buf, '/');
@@ -541,7 +541,7 @@
             
             if(seg_len > 0) {
                 cxstring seg = cx_strn(seg_ptr, seg_len);
-                if(!cx_strcmp(seg, CX_STR(".."))) {
+                if(!cx_strcmp(seg, cx_str(".."))) {
                     for(int j=buf.pos;j>=0;j--) {
                         char t = j < buf.pos ? buf.space[j] : 0;
                         if(IS_PATH_SEPARATOR(t) || j == 0) {
@@ -552,7 +552,7 @@
                             break;
                         }
                     }
-                } else if(!cx_strcmp(seg, CX_STR("."))) {
+                } else if(!cx_strcmp(seg, cx_str("."))) {
                     // ignore
                 } else {
                     if(add_separator) {
@@ -615,13 +615,13 @@
             }
         }
         
-        cxBufferInit(&out, NULL, dircount*3+path_len-last_dir, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+        cxBufferInit(&out, cxDefaultAllocator, NULL, dircount*3+path_len-last_dir, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
         
         for(size_t i=0;i<dircount;i++) {
             cxBufferPutString(&out, "../");
         }
     } else {
-        cxBufferInit(&out, NULL, path_len - last_dir, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+        cxBufferInit(&out, cxDefaultAllocator, NULL, path_len - last_dir, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     }
     
     cxBufferPutString(&out, abspath + last_dir + 1);
@@ -719,7 +719,7 @@
     if(p) {
         path = cx_str((char*)p);
     } else {
-        path = CX_STR("");
+        path = cx_str("");
     }
     
     return util_concat_path_s(base, path).ptr;
@@ -727,7 +727,7 @@
 
 cxmutstr util_concat_path_s(cxstring base, cxstring path) {
     if(!path.ptr) {
-        path = CX_STR("");
+        path = cx_str("");
     }
     
     int add_separator = 0;
@@ -743,7 +743,7 @@
     
     cxmutstr url;
     if(add_separator) {
-        url = cx_strcat(3, base, CX_STR("/"), path);
+        url = cx_strcat(3, base, cx_str("/"), path);
     } else {
         url = cx_strcat(2, base, path);
     }
@@ -753,7 +753,7 @@
 
 cxmutstr util_concat_path_ext(cxstring base, cxstring path, char separator) {
     if(!path.ptr) {
-        path = CX_STR("");
+        path = cx_str("");
     }
 
     int add_separator = 0;
@@ -809,7 +809,7 @@
     }
     
     CxBuffer url;
-    cxBufferInit(&url, NULL, 256, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&url, cxDefaultAllocator, NULL, 256, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     // add base url
     cxBufferWrite(sn->base_url, 1, strlen(sn->base_url), &url);
@@ -818,7 +818,7 @@
     
     cxstring p = cx_strn(path, pathlen);
     
-    CxStrtokCtx tkctx = cx_strtok(p, CX_STR("/"), INT_MAX);
+    CxStrtokCtx tkctx = cx_strtok(p, cx_str("/"), INT_MAX);
     cxstring node;
     while(cx_strtok_next(&tkctx, &node)) {
         if(node.length > 0) {
@@ -1155,7 +1155,7 @@
     unsigned char *str = malloc(25);
     str[24] = '\0';
     
-    cxstring t = CX_STR(
+    cxstring t = cx_str(
             "01234567890"
             "abcdefghijklmnopqrstuvwxyz"
             "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
@@ -1224,7 +1224,7 @@
 
 cxmutstr util_readline(FILE *stream) {
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 128, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, 128, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     int c;
     while((c = fgetc(stream)) != EOF) {
@@ -1260,7 +1260,7 @@
     
     // read password input
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, 128, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, 128, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     int c = 0;
     while((c = getpasswordchar()) != EOF) {
         if(c == '\n' || c == '\r') {
@@ -1335,7 +1335,7 @@
 char* util_hexstr(const unsigned char *data, size_t len) {
     size_t buflen = 2*len + 4;
     CxBuffer buf;
-    cxBufferInit(&buf, NULL, buflen + 1, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    cxBufferInit(&buf, cxDefaultAllocator, NULL, buflen + 1, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     for(int i=0;i<len;i++) {
         cx_bprintf(&buf, "%02x", data[i]);
     }
--- a/libidav/versioning.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/versioning.c	Fri Dec 19 17:53:18 2025 +0100
@@ -101,7 +101,7 @@
     
     // create a version-tree request, which is almost the same as propfind
     CxBuffer *rqbuf = create_propfind_request(sn, proplist, "version-tree", 1);
-    CxBuffer *rpbuf = cxBufferCreate(NULL, 4096, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *rpbuf = cxBufferCreate(cxDefaultAllocator, NULL, 4096, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     // do the request
     CURLcode ret = do_report_request(sn, rqbuf, rpbuf);
--- a/libidav/webdav.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/webdav.c	Fri Dec 19 17:53:18 2025 +0100
@@ -49,8 +49,8 @@
     if(!context) {
         return NULL;
     }
-    context->sessions = cxLinkedListCreate(cxDefaultAllocator, cx_cmp_ptr, CX_STORE_POINTERS);
-    cxDefineDestructor(context->sessions, dav_session_destructor);
+    context->sessions = cxLinkedListCreate(cxDefaultAllocator, CX_STORE_POINTERS);
+    cxSetDestructor(context->sessions, dav_session_destructor);
     context->http_proxy = calloc(1, sizeof(DavProxy));
     if(!context->http_proxy) {
         dav_context_destroy(context);
@@ -387,7 +387,7 @@
         proplist = parse_properties_string(sn->context, cx_str(properties));
     }
     CxBuffer *rqbuf = create_propfind_request(sn, proplist, "propfind", 0);
-    CxBuffer *rpbuf = cxBufferCreate(NULL, 4096, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *rpbuf = cxBufferCreate(cxDefaultAllocator, NULL, 4096, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     //fwrite(rqbuf->space, 1, rqbuf->size, stdout);
     //printf("\n");
@@ -432,7 +432,7 @@
     CURL *handle = sn->handle;
     util_set_url(sn, dav_resource_get_href(root));
      
-    CxBuffer *rpbuf = cxBufferCreate(NULL, 4096, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *rpbuf = cxBufferCreate(cxDefaultAllocator, NULL, 4096, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     DavResource *resource = root;
     CURLcode ret = do_propfind_request(sn, rqbuf, rpbuf);
     long status = 0;
@@ -454,7 +454,7 @@
 }
 
 CxList* parse_properties_string(DavContext *context, cxstring str) {
-    CxList *proplist = cxLinkedListCreateSimple(sizeof(DavProperty));
+    CxList *proplist = cxLinkedListCreate(NULL, sizeof(DavProperty));
     
     CxStrtokCtx tok = cx_strtok(str, cx_str(","), INT_MAX);
     cxstring s;
--- a/libidav/xml.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/libidav/xml.c	Fri Dec 19 17:53:18 2025 +0100
@@ -63,7 +63,7 @@
     ConvXmlElm ce;
     ce.node = node;
     ce.parent = NULL;
-    CxList *stack = cxLinkedListCreate(cxDefaultAllocator, NULL, sizeof(ConvXmlElm));
+    CxList *stack = cxLinkedListCreate(cxDefaultAllocator, sizeof(ConvXmlElm));
     if(!stack) {
         return NULL;
     }
--- a/make/gcc.mk	Sun Dec 07 20:16:59 2025 +0100
+++ b/make/gcc.mk	Fri Dec 19 17:53:18 2025 +0100
@@ -2,7 +2,7 @@
 # gcc toolchain config
 #
 
-CFLAGS = -std=gnu11
+CFLAGS = 
 DEBUG_CFLAGS = -g
 RELEASE_CFLAGS = -O3 -DNDEBUG
 LDFLAGS =
--- a/test/crypto.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/test/crypto.c	Fri Dec 19 17:53:18 2025 +0100
@@ -253,7 +253,7 @@
         DavKey *key = i < 16 ? &keys256[i] : &keys128[i%16];
         
         for(int j=0;j<20;j++) {
-            CxBuffer *content = cxBufferCreate(NULL, 256, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+            CxBuffer *content = cxBufferCreate(cxDefaultAllocator, NULL, 256, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
             cxBufferPutString(content, strings[j]);
             content->pos = 0;
             
@@ -285,9 +285,9 @@
 }
 
 UCX_TEST(test_crypto_stream) {
-    CxBuffer *data = cxBufferCreate(NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
-    CxBuffer *cbuf = cxBufferCreate(NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
-    CxBuffer *pbuf = cxBufferCreate(NULL, 1024, cxDefaultAllocator, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *data = cxBufferCreate(cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *cbuf = cxBufferCreate(cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
+    CxBuffer *pbuf = cxBufferCreate(cxDefaultAllocator, NULL, 1024, CX_BUFFER_FREE_CONTENTS|CX_BUFFER_AUTO_EXTEND);
     
     UCX_TEST_BEGIN;
     
--- a/test/main.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/test/main.c	Fri Dec 19 17:53:18 2025 +0100
@@ -47,7 +47,7 @@
 }
 #endif
 
-int test_main(int argc, char **argv) {
+int test_main(int argc, char **argv) { 
     printf("libidav tests\n");
     printf("-------------\n\n");
     
--- a/ucx/allocator.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/allocator.c	Fri Dec 19 17:53:18 2025 +0100
@@ -31,6 +31,35 @@
 #include <errno.h>
 #include <string.h>
 
+#ifdef _WIN32
+#include <Windows.h>
+#include <sysinfoapi.h>
+unsigned long cx_system_page_size(void) {
+    static unsigned long ps = 0;
+    if (ps == 0) {
+        SYSTEM_INFO sysinfo;
+        GetSystemInfo(&sysinfo);
+        ps = (unsigned long) sysinfo.dwPageSize;
+    }
+    return ps;
+}
+#else
+#include <unistd.h>
+unsigned long cx_system_page_size(void) {
+    static unsigned long ps = 0;
+    if (ps == 0) {
+        long sc = sysconf(_SC_PAGESIZE);
+        if (sc < 0) {
+            // fallback for systems which do not report a value here
+            ps = 4096; // LCOV_EXCL_LINE
+        } else {
+            ps = (unsigned long) sc;
+        }
+    }
+    return ps;
+}
+#endif
+
 static void *cx_malloc_stdlib(
         cx_attr_unused void *d,
         size_t n
@@ -79,6 +108,11 @@
         void **mem,
         size_t n
 ) {
+    if (n == 0) {
+        free(*mem);
+        *mem = NULL;
+        return 0;
+    }
     void *nmem = realloc(*mem, n);
     if (nmem == NULL) {
         return 1; // LCOV_EXCL_LINE
@@ -93,6 +127,11 @@
         size_t nmemb,
         size_t size
 ) {
+    if (nmemb == 0 || size == 0) {
+        free(*mem);
+        *mem = NULL;
+        return 0;
+    }
     size_t n;
     if (cx_szmul(nmemb, size, &n)) {
         errno = EOVERFLOW;
@@ -156,6 +195,11 @@
         void **mem,
         size_t n
 ) {
+    if (n == 0) {
+        cxFree(allocator, *mem);
+        *mem = NULL;
+        return 0;
+    }
     void *nmem = allocator->cl->realloc(allocator->data, *mem, n);
     if (nmem == NULL) {
         return 1; // LCOV_EXCL_LINE
@@ -171,6 +215,11 @@
         size_t nmemb,
         size_t size
 ) {
+    if (nmemb == 0 || size == 0) {
+        cxFree(allocator, *mem);
+        *mem = NULL;
+        return 0;
+    }
     void *nmem = cxReallocArray(allocator, *mem, nmemb, size);
     if (nmem == NULL) {
         return 1; // LCOV_EXCL_LINE
@@ -194,3 +243,7 @@
 ) {
     allocator->cl->free(allocator->data, mem);
 }
+
+void cxFreeDefault(void *mem) {
+    cxDefaultAllocator->cl->free(cxDefaultAllocator->data, mem);
+}
--- a/ucx/array_list.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/array_list.c	Fri Dec 19 17:53:18 2025 +0100
@@ -26,413 +26,192 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#ifdef WITH_MEMRCHR
+#define _GNU_SOURCE
+#endif
+
 #include "cx/array_list.h"
 #include "cx/compare.h"
 #include <assert.h>
 #include <string.h>
 #include <errno.h>
 
-// Default array reallocator
-
-static void *cx_array_default_realloc(
-        void *array,
-        cx_attr_unused size_t old_capacity,
-        size_t new_capacity,
-        size_t elem_size,
-        cx_attr_unused CxArrayReallocator *alloc
-) {
-    size_t n;
-    if (cx_szmul(new_capacity, elem_size, &n)) {
-        errno = EOVERFLOW;
-        return NULL;
-    }
-    return cxReallocDefault(array, n);
-}
-
-CxArrayReallocator cx_array_default_reallocator_impl = {
-        cx_array_default_realloc, NULL, NULL
-};
-
-CxArrayReallocator *cx_array_default_reallocator = &cx_array_default_reallocator_impl;
-
-// Stack-aware array reallocator
-
-static void *cx_array_advanced_realloc(
-        void *array,
-        size_t old_capacity,
-        size_t new_capacity,
-        size_t elem_size,
-        cx_attr_unused CxArrayReallocator *alloc
-) {
-    // check for overflow
-    size_t n;
-    if (cx_szmul(new_capacity, elem_size, &n)) {
-        errno = EOVERFLOW;
-        return NULL;
-    }
-
-    // retrieve the pointer to the actual allocator
-    const CxAllocator *al = alloc->allocator;
-
-    // check if the array is still located on the stack
-    void *newmem;
-    if (array == alloc->stack_ptr) {
-        newmem = cxMalloc(al, n);
-        if (newmem != NULL && array != NULL) {
-            memcpy(newmem, array, old_capacity*elem_size);
-        }
-    } else {
-        newmem = cxRealloc(al, array, n);
-    }
-    return newmem;
-}
-
-struct cx_array_reallocator_s cx_array_reallocator(
-        const struct cx_allocator_s *allocator,
-        const void *stack_ptr
-) {
-    if (allocator == NULL) {
-        allocator = cxDefaultAllocator;
-    }
-    return (struct cx_array_reallocator_s) {
-            cx_array_advanced_realloc,
-            allocator, stack_ptr,
-    };
-}
-
 // LOW LEVEL ARRAY LIST FUNCTIONS
 
 /**
- * Increases the capacity until it is a multiple of a some alignment or reaches the maximum.
+ * Intelligently calculates a new capacity, reserving some more
+ * elements than required to prevent too many allocations.
  *
- * @param cap the required capacity (must not be larger than @p max)
- * @param alignment the alignment
- * @param max the maximum capacity
- * @return the aligned capacity
+ * @param current_capacity the current capacity of the array
+ * @param needed_capacity the required capacity of the array
+ * @return the new capacity
  */
-static size_t cx_array_align_capacity(
-        size_t cap,
-        size_t alignment,
-        size_t max
+static size_t cx_array_grow_capacity(
+    size_t current_capacity,
+    size_t needed_capacity
 ) {
-    if (cap > max - alignment) {
-        return cap;
-    } else {
-        return cap - (cap % alignment) + alignment;
+    if (current_capacity >= needed_capacity) {
+        return current_capacity;
     }
+    size_t cap = needed_capacity;
+    size_t alignment;
+    if (cap < 128) alignment = 16;
+    else if (cap < 1024) alignment = 64;
+    else if (cap < 8192) alignment = 512;
+    else alignment = 1024;
+    return cap - (cap % alignment) + alignment;
+}
+
+int cx_array_init_(const CxAllocator *allocator, CxArray *array, size_t elem_size, size_t capacity) {
+    memset(array, 0, sizeof(CxArray));
+    return cx_array_reserve_(allocator, array, elem_size, capacity);
+}
+
+void cx_array_init_fixed_(CxArray *array, const void *data, size_t capacity, size_t size) {
+    array->data = (void*) data;
+    array->capacity = capacity;
+    array->size = size;
 }
 
-int cx_array_reserve(
-        void **array,
-        void *size,
-        void *capacity,
-        unsigned width,
-        size_t elem_size,
-        size_t elem_count,
-        CxArrayReallocator *reallocator
-) {
-    // assert pointers
-    assert(array != NULL);
-    assert(size != NULL);
-    assert(capacity != NULL);
+int cx_array_reserve_(const CxAllocator *allocator, CxArray *array, size_t elem_size, size_t capacity) {
+    if (cxReallocateArray(allocator, &array->data, capacity, elem_size)) {
+        return -1; // LCOV_EXCL_LINE
+    }
+    array->capacity = capacity;
+    if (array->size > capacity) {
+        array->size = capacity;
+    }
+    return 0;
+}
 
-    // default reallocator
-    if (reallocator == NULL) {
-        reallocator = cx_array_default_reallocator;
+int cx_array_copy_to_new_(const CxAllocator *allocator, CxArray *array, size_t elem_size, size_t capacity) {
+    CxArray heap_array;
+    if (cx_array_init_(allocator, &heap_array, elem_size, capacity)) {
+        return -1; // LCOV_EXCL_LINE
+    }
+    heap_array.size = array->size;
+    memcpy(heap_array.data, array->data, elem_size * array->size);
+    *array = heap_array;
+    return 0;
+}
+
+int cx_array_insert_(const CxAllocator *allocator, CxArray *array,
+        size_t elem_size, size_t index, const void *other, size_t n) {
+    // out of bounds and special case check
+    if (index > array->size) return -1;
+    if (n == 0) return 0;
+
+    // guarantee enough capacity
+    if (array->capacity < array->size + n) {
+        const size_t new_capacity = cx_array_grow_capacity(array->capacity,array->size + n);
+        if (cxReallocateArray(allocator, &array->data, new_capacity, elem_size)) {
+            return -1; // LCOV_EXCL_LINE
+        }
+        array->capacity = new_capacity;
     }
 
-    // determine size and capacity
-    size_t oldcap;
-    size_t oldsize;
-    size_t max_size;
-    if (width == 0 || width == sizeof(size_t)) {
-        oldcap = *(size_t*) capacity;
-        oldsize = *(size_t*) size;
-        max_size = SIZE_MAX;
-    } else if (width == sizeof(uint16_t)) {
-        oldcap = *(uint16_t*) capacity;
-        oldsize = *(uint16_t*) size;
-        max_size = UINT16_MAX;
-    } else if (width == sizeof(uint8_t)) {
-        oldcap = *(uint8_t*) capacity;
-        oldsize = *(uint8_t*) size;
-        max_size = UINT8_MAX;
-    }
-#if CX_WORDSIZE == 64
-    else if (width == sizeof(uint32_t)) {
-        oldcap = *(uint32_t*) capacity;
-        oldsize = *(uint32_t*) size;
-        max_size = UINT32_MAX;
-    }
-#endif
-    else {
-        errno = EINVAL;
-        return 1;
+    // determine insert position
+    char *dst = array->data;
+    dst += index * elem_size;
+
+    // do we need to move some elements?
+    if (index < array->size) {
+        size_t elems_to_move = array->size - index;
+        char *target = dst + n * elem_size;
+        memmove(target, dst, elems_to_move * elem_size);
     }
 
-    // assert that the array is allocated when it has capacity
-    assert(*array != NULL || oldcap == 0);
-
-    // check for overflow
-    if (elem_count > max_size - oldsize) {
-        errno = EOVERFLOW;
-        return 1;
+    // place the new elements, if any
+    // otherwise, this function just reserved the memory (a.k.a emplace)
+    if (other != NULL) {
+        memcpy(dst, other, n * elem_size);
     }
-
-    // determine new capacity
-    size_t newcap = oldsize + elem_count;
-
-    // reallocate if possible
-    if (newcap > oldcap) {
-        // calculate new capacity (next number divisible by 16)
-        newcap = cx_array_align_capacity(newcap, 16, max_size);
-
-        // perform reallocation
-        void *newmem = reallocator->realloc(
-                *array, oldcap, newcap, elem_size, reallocator
-        );
-        if (newmem == NULL) {
-            return 1; // LCOV_EXCL_LINE
-        }
-
-        // store new pointer
-        *array = newmem;
-
-        // store new capacity
-        if (width == 0 || width == sizeof(size_t)) {
-            *(size_t*) capacity = newcap;
-        } else if (width == sizeof(uint16_t)) {
-            *(uint16_t*) capacity = (uint16_t) newcap;
-        } else if (width == sizeof(uint8_t)) {
-            *(uint8_t*) capacity = (uint8_t) newcap;
-        }
-#if CX_WORDSIZE == 64
-        else if (width == sizeof(uint32_t)) {
-            *(uint32_t*) capacity = (uint32_t) newcap;
-        }
-#endif
-    }
+    array->size += n;
 
     return 0;
 }
 
-int cx_array_copy(
-        void **target,
-        void *size,
-        void *capacity,
-        unsigned width,
-        size_t index,
-        const void *src,
+int cx_array_insert_sorted_c_(
+        const CxAllocator *allocator,
+        CxArray *array,
         size_t elem_size,
-        size_t elem_count,
-        CxArrayReallocator *reallocator
+        const void *sorted_data,
+        size_t n,
+        cx_compare_func2 cmp_func,
+        void *context,
+        bool allow_duplicates
 ) {
     // assert pointers
-    assert(target != NULL);
-    assert(size != NULL);
-    assert(capacity != NULL);
-    assert(src != NULL);
-
-    // default reallocator
-    if (reallocator == NULL) {
-        reallocator = cx_array_default_reallocator;
-    }
+    assert(allocator != NULL);
+    assert(array != NULL);
+    assert(cmp_func != NULL);
+    assert(sorted_data != NULL);
 
-    // determine size and capacity
-    size_t oldcap;
-    size_t oldsize;
-    size_t max_size;
-    if (width == 0 || width == sizeof(size_t)) {
-        oldcap = *(size_t*) capacity;
-        oldsize = *(size_t*) size;
-        max_size = SIZE_MAX;
-    } else if (width == sizeof(uint16_t)) {
-        oldcap = *(uint16_t*) capacity;
-        oldsize = *(uint16_t*) size;
-        max_size = UINT16_MAX;
-    } else if (width == sizeof(uint8_t)) {
-        oldcap = *(uint8_t*) capacity;
-        oldsize = *(uint8_t*) size;
-        max_size = UINT8_MAX;
-    }
-#if CX_WORDSIZE == 64
-    else if (width == sizeof(uint32_t)) {
-        oldcap = *(uint32_t*) capacity;
-        oldsize = *(uint32_t*) size;
-        max_size = UINT32_MAX;
-    }
-#endif
-    else {
-        errno = EINVAL;
-        return 1;
-    }
+    // corner case
+    if (n == 0) return 0;
 
-    // assert that the array is allocated when it has capacity
-    assert(*target != NULL || oldcap == 0);
-
-    // check for overflow
-    if (index > max_size || elem_count > max_size - index) {
+    // overflow check
+    // LCOV_EXCL_START
+    if (n > SIZE_MAX - array->size) {
         errno = EOVERFLOW;
         return 1;
     }
-
-    // check if resize is required
-    size_t minsize = index + elem_count;
-    size_t newsize = oldsize < minsize ? minsize : oldsize;
-
-    // reallocate if possible
-    size_t newcap = oldcap;
-    if (newsize > oldcap) {
-        // check, if we need to repair the src pointer
-        uintptr_t targetaddr = (uintptr_t) *target;
-        uintptr_t srcaddr = (uintptr_t) src;
-        bool repairsrc = targetaddr <= srcaddr
-                         && srcaddr < targetaddr + oldcap * elem_size;
-
-        // calculate new capacity (next number divisible by 16)
-        newcap = cx_array_align_capacity(newsize, 16, max_size);
-        assert(newcap > newsize);
-
-        // perform reallocation
-        void *newmem = reallocator->realloc(
-                *target, oldcap, newcap, elem_size, reallocator
-        );
-        if (newmem == NULL) {
-            return 1; // LCOV_EXCL_LINE
-        }
-
-        // repair src pointer, if necessary
-        if (repairsrc) {
-            src = ((char *) newmem) + (srcaddr - targetaddr);
-        }
-
-        // store new pointer
-        *target = newmem;
-    }
-
-    // determine target pointer
-    char *start = *target;
-    start += index * elem_size;
-
-    // copy elements and set new size
-    // note: no overflow check here, b/c we cannot get here w/o allocation
-    memmove(start, src, elem_count * elem_size);
-
-    // if any of size or capacity changed, store them back
-    if (newsize != oldsize || newcap != oldcap) {
-        if (width == 0 || width == sizeof(size_t)) {
-            *(size_t*) capacity = newcap;
-            *(size_t*) size = newsize;
-        } else if (width == sizeof(uint16_t)) {
-            *(uint16_t*) capacity = (uint16_t) newcap;
-            *(uint16_t*) size = (uint16_t) newsize;
-        } else if (width == sizeof(uint8_t)) {
-            *(uint8_t*) capacity = (uint8_t) newcap;
-            *(uint8_t*) size = (uint8_t) newsize;
-        }
-#if CX_WORDSIZE == 64
-        else if (width == sizeof(uint32_t)) {
-            *(uint32_t*) capacity = (uint32_t) newcap;
-            *(uint32_t*) size = (uint32_t) newsize;
-        }
-#endif
-    }
-
-    // return successfully
-    return 0;
-}
-
-static int cx_array_insert_sorted_impl(
-        void **target,
-        size_t *size,
-        size_t *capacity,
-        cx_compare_func cmp_func,
-        const void *sorted_data,
-        size_t elem_size,
-        size_t elem_count,
-        CxArrayReallocator *reallocator,
-        bool allow_duplicates
-) {
-    // assert pointers
-    assert(target != NULL);
-    assert(size != NULL);
-    assert(capacity != NULL);
-    assert(cmp_func != NULL);
-    assert(sorted_data != NULL);
-
-    // default reallocator
-    if (reallocator == NULL) {
-        reallocator = cx_array_default_reallocator;
-    }
-
-    // corner case
-    if (elem_count == 0) return 0;
-
-    // overflow check
-    if (elem_count > SIZE_MAX - *size) {
-        errno = EOVERFLOW;
-        return 1;
-    }
+    // LCOV_EXCL_STOP
 
     // store some counts
-    size_t old_size = *size;
-    size_t old_capacity = *capacity;
+    const size_t old_size = array->size;
+    const size_t old_capacity = array->capacity;
     // the necessary capacity is the worst case assumption, including duplicates
-    size_t needed_capacity = old_size + elem_count;
+    const size_t needed_capacity = cx_array_grow_capacity(old_capacity, old_size + n);
 
     // if we need more than we have, try a reallocation
     if (needed_capacity > old_capacity) {
-        size_t new_capacity = cx_array_align_capacity(needed_capacity, 16, SIZE_MAX);
-        void *new_mem = reallocator->realloc(
-                *target, old_capacity, new_capacity, elem_size, reallocator
-        );
-        if (new_mem == NULL) {
-            // give it up right away, there is no contract
-            // that requires us to insert as much as we can
-            return 1;  // LCOV_EXCL_LINE
+        if (cxReallocateArray(allocator, &array->data, needed_capacity, elem_size)) {
+            return -1; // LCOV_EXCL_LINE
         }
-        *target = new_mem;
-        *capacity = new_capacity;
+        array->capacity = needed_capacity;
     }
 
     // now we have guaranteed that we can insert everything
-    size_t new_size = old_size + elem_count;
-    *size = new_size;
+    size_t new_size = old_size + n;
+    array->size = new_size;
 
     // declare the source and destination indices/pointers
     size_t si = 0, di = 0;
     const char *src = sorted_data;
-    char *dest = *target;
+    char *dest = array->data;
 
     // find the first insertion point
-    di = cx_array_binary_search_sup(dest, old_size, elem_size, src, cmp_func);
+    di = cx_array_binary_search_sup_c(dest, old_size, elem_size, src, cmp_func, context);
     dest += di * elem_size;
 
     // move the remaining elements in the array completely to the right
     // we will call it the "buffer" for parked elements
     size_t buf_size = old_size - di;
     size_t bi = new_size - buf_size;
-    char *bptr = ((char *) *target) + bi * elem_size;
+    char *bptr = ((char *) array->data) + bi * elem_size;
     memmove(bptr, dest, buf_size * elem_size);
 
     // while there are both source and buffered elements left,
     // copy them interleaving
-    while (si < elem_count && bi < new_size) {
-        // determine how many source elements can be inserted
+    while (si < n && bi < new_size) {
+        // determine how many source elements can be inserted.
+        // the first element that shall not be inserted is the smallest element
+        // that is strictly larger than the first buffered element
+        // (located at the index of the infimum plus one).
+        // the infimum is guaranteed to exist:
+        // - if all src elements are larger,
+        //   there is no buffer, and this loop is skipped
+        // - if any src element is smaller or equal, the infimum exists
+        // - when all src elements that are smaller are copied, the second part
+        //   of this loop body will copy the remaining buffer (emptying it)
+        // Therefore, the buffer can never contain an element that is smaller
+        // than any element in the source and the infimum exists.
         size_t copy_len, bytes_copied;
-        copy_len = cx_array_binary_search_sup(
-                src,
-                elem_count - si,
-                elem_size,
-                bptr,
-                cmp_func
+        copy_len = cx_array_binary_search_inf_c(
+            src, n - si, elem_size, bptr, cmp_func, context
         );
-        // binary search gives us the smallest index;
-        // we also want to include equal elements here
-        while (si + copy_len < elem_count
-                && cmp_func(bptr, src+copy_len*elem_size) == 0) {
-            copy_len++;
-        }
+        copy_len++;
 
         // copy the source elements
         if (copy_len > 0) {
@@ -449,17 +228,17 @@
                 // for being a duplicate of the bptr
                 const char *end_of_src = src + (copy_len - 1) * elem_size;
                 size_t skip_len = 0;
-                while (copy_len > 0 && cmp_func(bptr, end_of_src) == 0) {
+                while (copy_len > 0 && cmp_func(bptr, end_of_src, context) == 0) {
                     end_of_src -= elem_size;
                     skip_len++;
                     copy_len--;
                 }
-                char *last = dest == *target ? NULL : dest - elem_size;
+                char *last = dest == array->data ? NULL : dest - elem_size;
                 // then iterate through the source chunk
                 // and skip all duplicates with the last element in the array
                 size_t more_skipped = 0;
                 for (unsigned j = 0; j < copy_len; j++) {
-                    if (last != NULL && cmp_func(last, src) == 0) {
+                    if (last != NULL && cmp_func(last, src, context) == 0) {
                         // duplicate - skip
                         src += elem_size;
                         si++;
@@ -478,20 +257,21 @@
                 si += skip_len;
                 skip_len += more_skipped;
                 // reduce the actual size by the number of skipped elements
-                *size -= skip_len;
+                array->size -= skip_len;
             }
         }
 
         // when all source elements are in place, we are done
-        if (si >= elem_count) break;
+        if (si >= n) break;
 
         // determine how many buffered elements need to be restored
-        copy_len = cx_array_binary_search_sup(
+        copy_len = cx_array_binary_search_sup_c(
                 bptr,
                 new_size - bi,
                 elem_size,
                 src,
-                cmp_func
+                cmp_func,
+                context
         );
 
         // restore the buffered elements
@@ -504,33 +284,24 @@
     }
 
     // still source elements left?
-    if (si < elem_count) {
+    if (si < n) {
         if (allow_duplicates) {
             // duplicates allowed or nothing inserted yet: simply copy everything
-            memcpy(dest, src, elem_size * (elem_count - si));
+            memcpy(dest, src, elem_size * (n - si));
         } else {
-            if (dest != *target) {
-                // skip all source elements that equal the last element
-                char *last = dest - elem_size;
-                while (si < elem_count) {
-                    if (last != NULL && cmp_func(last, src) == 0) {
-                        src += elem_size;
-                        si++;
-                        (*size)--;
-                    } else {
-                        break;
-                    }
-                }
-            }
-            // we must check the elements in the chunk one by one
-            while (si < elem_count) {
+            // we must check the remaining source elements one by one
+            // to skip the duplicates.
+            // Note that no source element can equal the last element in the
+            // destination, because that would have created an insertion point
+            // and a buffer, s.t. the above loop already handled the duplicates
+            while (si < n) {
                 // find a chain of elements that can be copied
                 size_t copy_len = 1, skip_len = 0;
                 {
                     const char *left_src = src;
-                    while (si + copy_len < elem_count) {
+                    while (si + copy_len + skip_len < n) {
                         const char *right_src = left_src + elem_size;
-                        int d = cmp_func(left_src,  right_src);
+                        int d = cmp_func(left_src,  right_src, context);
                         if (d < 0) {
                             if (skip_len > 0) {
                                 // new larger element found;
@@ -553,13 +324,13 @@
                 src += bytes_copied + skip_len * elem_size;
                 si += copy_len + skip_len;
                 di += copy_len;
-                *size -= skip_len;
+                array->size -= skip_len;
             }
         }
     }
 
     // buffered elements need to be moved when we skipped duplicates
-    size_t total_skipped = new_size - *size;
+    size_t total_skipped = new_size - array->size;
     if (bi < new_size && total_skipped > 0) {
         // move the remaining buffer to the end of the array
         memmove(dest, bptr, elem_size * (new_size - bi));
@@ -568,40 +339,116 @@
     return 0;
 }
 
-int cx_array_insert_sorted(
-        void **target,
-        size_t *size,
-        size_t *capacity,
-        cx_compare_func cmp_func,
+int cx_array_insert_sorted_(
+        const CxAllocator *allocator,
+        CxArray *array,
+        size_t elem_size,
         const void *sorted_data,
-        size_t elem_size,
-        size_t elem_count,
-        CxArrayReallocator *reallocator
+        size_t n,
+        cx_compare_func cmp_func,
+        bool allow_duplicates
 ) {
-    return cx_array_insert_sorted_impl(target, size, capacity,
-        cmp_func, sorted_data, elem_size, elem_count, reallocator, true);
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    return cx_array_insert_sorted_c_(allocator, array, elem_size, sorted_data,
+        n, cx_ccmp_wrap, &wrapper, allow_duplicates);
+}
+
+#ifndef WITH_QSORT_R
+static thread_local cx_compare_func2 cx_array_fn_for_qsort;
+static thread_local void *cx_array_context_for_qsort;
+static int cx_array_qsort_wrapper(const void *l, const void *r) {
+    return cx_array_fn_for_qsort(l, r, cx_array_context_for_qsort);
+}
+#endif
+
+void cx_array_qsort_c(void *array, size_t nmemb, size_t size,
+        cx_compare_func2 fn, void *context) {
+#ifdef WITH_QSORT_R
+    qsort_r(array, nmemb, size, fn, context);
+#else
+    cx_array_fn_for_qsort = fn;
+    cx_array_context_for_qsort = context;
+    qsort(array, nmemb, size, cx_array_qsort_wrapper);
+#endif
+}
+
+void cx_array_sort_(CxArray *array, size_t elem_size,
+        cx_compare_func fn) {
+    qsort(array->data, array->size, elem_size, fn);
+}
+
+void cx_array_sort_c_(CxArray *array, size_t elem_size,
+        cx_compare_func2 fn, void *context) {
+    cx_array_qsort_c(array->data, array->size, elem_size, fn, context);
+}
+
+CxIterator cx_array_iterator_(CxArray *array, size_t elem_size) {
+    return cxIterator(array->data, elem_size, array->size);
+}
+
+CxIterator cx_array_iterator_ptr_(CxArray *array) {
+    return cxIteratorPtr(array->data, array->size);
 }
 
-int cx_array_insert_unique(
-        void **target,
-        size_t *size,
-        size_t *capacity,
-        cx_compare_func cmp_func,
-        const void *sorted_data,
-        size_t elem_size,
-        size_t elem_count,
-        CxArrayReallocator *reallocator
-) {
-    return cx_array_insert_sorted_impl(target, size, capacity,
-        cmp_func, sorted_data, elem_size, elem_count, reallocator, false);
+void cx_array_remove_(CxArray *array, size_t elem_size, size_t index, size_t n, bool fast) {
+    if (n == 0) return;
+    if (index >= array->size) return;
+    if (index + n >= array->size) {
+        // only tail elements are removed
+        array->size = index;
+        return;
+    }
+    array->size -= n;
+    size_t remaining = array->size - index;
+    char *dest = ((char*)array->data) + index * elem_size;
+    if (fast) {
+        char *src = dest + remaining * elem_size;
+        if (n == 1 && elem_size <= CX_WORDSIZE/8) {
+            // try to optimize int-sized values
+            // (from likely to unlikely)
+            if (elem_size == sizeof(int32_t)) {
+                *(int32_t*)dest = *(int32_t*)src;
+                return;
+            }
+#if CX_WORDSIZE == 64
+            if (elem_size == sizeof(int64_t)) {
+                *(int64_t*)dest = *(int64_t*)src;
+                return;
+            }
+#endif
+            if (elem_size == sizeof(int8_t)) {
+                *(int8_t*)dest = *(int8_t*)src;
+                return;
+            }
+            if (elem_size == sizeof(int16_t)) {
+                *(int16_t*)dest = *(int16_t*)src;
+                return;
+            }
+            // note we cannot optimize the last branch, because
+            // the elem_size could be crazily misaligned
+        }
+        memcpy(dest, src, n * elem_size);
+    } else {
+        char *src = dest + n * elem_size;
+        memmove(dest, src, remaining * elem_size);
+    }
 }
 
-size_t cx_array_binary_search_inf(
+void cx_array_free_(const CxAllocator *allocator, CxArray *array) {
+    cxFree(allocator, array->data);
+    array->data = NULL;
+    array->size = array->capacity = 0;
+}
+
+
+// implementation that finds ANY index
+static size_t cx_array_binary_search_inf_impl(
         const void *arr,
         size_t size,
         size_t elem_size,
         const void *elem,
-        cx_compare_func cmp_func
+        cx_compare_func2 cmp_func,
+        void *context
 ) {
     // special case: empty array
     if (size == 0) return 0;
@@ -613,7 +460,7 @@
     const char *array = arr;
 
     // check the first array element
-    result = cmp_func(elem, array);
+    result = cmp_func(elem, array, context);
     if (result < 0) {
         return size;
     } else if (result == 0) {
@@ -624,7 +471,7 @@
     if (size == 1) return 0;
 
     // check the last array element
-    result = cmp_func(elem, array + elem_size * (size - 1));
+    result = cmp_func(elem, array + elem_size * (size - 1), context);
     if (result >= 0) {
         return size - 1;
     }
@@ -633,21 +480,14 @@
     // so start the binary search
     size_t left_index = 1;
     size_t right_index = size - 1;
-    size_t pivot_index;
+    size_t pivot_index = 0;
 
     while (left_index <= right_index) {
         pivot_index = left_index + (right_index - left_index) / 2;
         const char *arr_elem = array + pivot_index * elem_size;
-        result = cmp_func(elem, arr_elem);
+        result = cmp_func(elem, arr_elem, context);
         if (result == 0) {
             // found it!
-            // check previous elements;
-            // when they are equal, report the smallest index
-            arr_elem -= elem_size;
-            while (pivot_index > 0 && cmp_func(elem, arr_elem) == 0) {
-                pivot_index--;
-                arr_elem -= elem_size;
-            }
             return pivot_index;
         } else if (result < 0) {
             // element is smaller than pivot, continue search left
@@ -662,6 +502,85 @@
     return result < 0 ? (pivot_index - 1) : pivot_index;
 }
 
+size_t cx_array_binary_search_inf_c(
+        const void *arr,
+        size_t size,
+        size_t elem_size,
+        const void *elem,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    size_t index = cx_array_binary_search_inf_impl(
+        arr, size, elem_size, elem, cmp_func, context);
+    // in case of equality, report the largest index
+    const char *e = ((const char *) arr) + (index + 1) * elem_size;
+    while (index + 1 < size && cmp_func(e, elem, context) == 0) {
+        e += elem_size;
+        index++;
+    }
+    return index;
+}
+
+size_t cx_array_binary_search_c(
+        const void *arr,
+        size_t size,
+        size_t elem_size,
+        const void *elem,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    size_t index = cx_array_binary_search_inf_c(
+            arr, size, elem_size, elem, cmp_func, context
+    );
+    if (index < size && cmp_func(((const char *) arr) + index * elem_size,
+        elem, context) == 0) {
+        return index;
+    } else {
+        return size;
+    }
+}
+
+size_t cx_array_binary_search_sup_c(
+        const void *arr,
+        size_t size,
+        size_t elem_size,
+        const void *elem,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    size_t index = cx_array_binary_search_inf_impl(
+            arr, size, elem_size, elem, cmp_func, context
+    );
+    const char *e = ((const char *) arr) + index * elem_size;
+    if (index == size) {
+        // no infimum means the first element is supremum
+        return 0;
+    } else if (cmp_func(e, elem, context) == 0) {
+        // found an equal element, search the smallest index
+        e -= elem_size; // e now contains the element at index-1
+        while (index > 0 && cmp_func(e, elem, context) == 0) {
+            e -= elem_size;
+            index--;
+        }
+        return index;
+    } else {
+        // we already have the largest index of the infimum (by design)
+        // the next element is the supremum (or there is no supremum)
+        return index + 1;
+    }
+}
+
+size_t cx_array_binary_search_inf(
+        const void *arr,
+        size_t size,
+        size_t elem_size,
+        const void *elem,
+        cx_compare_func cmp_func
+) {
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    return cx_array_binary_search_inf_c(arr, size, elem_size, elem, cx_ccmp_wrap, &wrapper);
+}
+
 size_t cx_array_binary_search(
         const void *arr,
         size_t size,
@@ -669,15 +588,8 @@
         const void *elem,
         cx_compare_func cmp_func
 ) {
-    size_t index = cx_array_binary_search_inf(
-            arr, size, elem_size, elem, cmp_func
-    );
-    if (index < size &&
-            cmp_func(((const char *) arr) + index * elem_size, elem) == 0) {
-        return index;
-    } else {
-        return size;
-    }
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    return cx_array_binary_search_c(arr, size, elem_size, elem, cx_ccmp_wrap, &wrapper);
 }
 
 size_t cx_array_binary_search_sup(
@@ -687,17 +599,8 @@
         const void *elem,
         cx_compare_func cmp_func
 ) {
-    size_t inf = cx_array_binary_search_inf(
-            arr, size, elem_size, elem, cmp_func
-    );
-    if (inf == size) {
-        // no infimum means, first element is supremum
-        return 0;
-    } else if (cmp_func(((const char *) arr) + inf * elem_size, elem) == 0) {
-        return inf;
-    } else {
-        return inf + 1;
-    }
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    return cx_array_binary_search_sup_c(arr, size, elem_size, elem, cx_ccmp_wrap, &wrapper);
 }
 
 #ifndef CX_ARRAY_SWAP_SBO_SIZE
@@ -750,7 +653,6 @@
     struct cx_list_s base;
     void *data;
     size_t capacity;
-    CxArrayReallocator reallocator;
 } cx_array_list;
 
 static void cx_arl_destructor(struct cx_list_s *list) {
@@ -781,43 +683,47 @@
         const void *array,
         size_t n
 ) {
-    // out of bounds and special case check
-    if (index > list->collection.size || n == 0) return 0;
-
-    // get a correctly typed pointer to the list
     cx_array_list *arl = (cx_array_list *) list;
-
-    // guarantee enough capacity
-    if (arl->capacity < list->collection.size + n) {
-        size_t new_capacity = list->collection.size + n;
-        new_capacity = cx_array_align_capacity(new_capacity, 16, SIZE_MAX);
-        if (cxReallocateArray(
-                list->collection.allocator,
-                &arl->data, new_capacity,
-                list->collection.elem_size)
-        ) {
-            return 0;
-        }
-        arl->capacity = new_capacity;
+    CxArray wrap = {
+        arl->data, list->collection.size, arl->capacity
+    };
+    if (cx_array_insert_(list->collection.allocator, &wrap,
+            list->collection.elem_size, index, array, n)) {
+        return 0;
     }
+    arl->data = wrap.data;
+    arl->capacity = wrap.capacity;
+    list->collection.size = wrap.size;
+    return n;
+}
 
-    // determine insert position
-    char *arl_data = arl->data;
-    char *insert_pos = arl_data + index * list->collection.elem_size;
+static size_t cx_arl_insert_sorted_impl(
+        struct cx_list_s *list,
+        const void *sorted_data,
+        size_t n,
+        bool allow_duplicates
+) {
+    cx_array_list *arl = (cx_array_list *) list;
+    CxArray wrap = {
+        arl->data, list->collection.size, arl->capacity
+    };
 
-    // do we need to move some elements?
-    if (index < list->collection.size) {
-        size_t elems_to_move = list->collection.size - index;
-        char *target = insert_pos + n * list->collection.elem_size;
-        memmove(target, insert_pos, elems_to_move * list->collection.elem_size);
+    if (cx_array_insert_sorted_c_(
+            list->collection.allocator,
+            &wrap,
+            list->collection.elem_size,
+            sorted_data,
+            n,
+            cx_list_compare_wrapper,
+            list,
+            allow_duplicates
+    )) {
+        // array list implementation is "all or nothing"
+        return 0;  // LCOV_EXCL_LINE
     }
-
-    // place the new elements, if any
-    if (array != NULL) {
-        memcpy(insert_pos, array, n * list->collection.elem_size);
-    }
-    list->collection.size += n;
-
+    arl->data = wrap.data;
+    arl->capacity = wrap.capacity;
+    list->collection.size = wrap.size;
     return n;
 }
 
@@ -826,24 +732,7 @@
         const void *sorted_data,
         size_t n
 ) {
-    // get a correctly typed pointer to the list
-    cx_array_list *arl = (cx_array_list *) list;
-
-    if (cx_array_insert_sorted(
-            &arl->data,
-            &list->collection.size,
-            &arl->capacity,
-            list->collection.cmpfunc,
-            sorted_data,
-            list->collection.elem_size,
-            n,
-            &arl->reallocator
-    )) {
-        // array list implementation is "all or nothing"
-        return 0;
-    } else {
-        return n;
-    }
+    return cx_arl_insert_sorted_impl(list, sorted_data, n, true);
 }
 
 static size_t cx_arl_insert_unique(
@@ -851,24 +740,7 @@
         const void *sorted_data,
         size_t n
 ) {
-    // get a correctly typed pointer to the list
-    cx_array_list *arl = (cx_array_list *) list;
-
-    if (cx_array_insert_unique(
-            &arl->data,
-            &list->collection.size,
-            &arl->capacity,
-            list->collection.cmpfunc,
-            sorted_data,
-            list->collection.elem_size,
-            n,
-            &arl->reallocator
-    )) {
-        // array list implementation is "all or nothing"
-        return 0;
-    } else {
-        return n;
-    }
+    return cx_arl_insert_sorted_impl(list, sorted_data, n, false);
 }
 
 static void *cx_arl_insert_element(
@@ -892,7 +764,7 @@
     if (iter->index < list->collection.size) {
         if (cx_arl_insert_element(list,
                 iter->index + 1 - prepend, elem) == NULL) {
-            return 1;
+            return 1; // LCOV_EXCL_LINE
         }
         iter->elem_count++;
         if (prepend != 0) {
@@ -902,7 +774,7 @@
         return 0;
     } else {
         if (cx_arl_insert_element(list, list->collection.size, elem) == NULL) {
-            return 1;
+            return 1;  // LCOV_EXCL_LINE
         }
         iter->elem_count++;
         iter->index = list->collection.size;
@@ -947,24 +819,20 @@
         );
     }
 
+    // calculate how many elements would need to be moved
+    size_t remaining = list->collection.size - index - remove;
+
     // short-circuit removal of last elements
-    if (index + remove == list->collection.size) {
+    if (remaining == 0) {
         list->collection.size -= remove;
         return remove;
     }
 
     // just move the elements to the left
-    cx_array_copy(
-            &arl->data,
-            &list->collection.size,
-            &arl->capacity,
-            0,
-            index,
-            ((char *) arl->data) + (index + remove) * list->collection.elem_size,
-            list->collection.elem_size,
-            list->collection.size - index - remove,
-            &arl->reallocator
-    );
+    char *dst_move = arl->data;
+    dst_move += index * list->collection.elem_size;
+    char *first_remaining = dst_move + remove * list->collection.elem_size;
+    memmove(dst_move, first_remaining, remaining * list->collection.elem_size);
 
     // decrease the size
     list->collection.size -= remove;
@@ -1025,18 +893,18 @@
         bool remove
 ) {
     assert(list != NULL);
-    assert(list->collection.cmpfunc != NULL);
     if (list->collection.size == 0) return 0;
     char *cur = ((const cx_array_list *) list)->data;
 
     // optimize with binary search, when sorted
     if (list->collection.sorted) {
-        size_t i = cx_array_binary_search(
+        size_t i = cx_array_binary_search_c(
             cur,
             list->collection.size,
             list->collection.elem_size,
             elem,
-            list->collection.cmpfunc
+            cx_list_compare_wrapper,
+            list
         );
         if (remove && i < list->collection.size) {
             cx_arl_remove(list, i, 1, NULL);
@@ -1046,7 +914,7 @@
 
     // fallback: linear search
     for (size_t i = 0; i < list->collection.size; i++) {
-        if (0 == list->collection.cmpfunc(elem, cur)) {
+        if (0 == cx_list_compare_wrapper(elem, cur, list)) {
             if (remove) {
                 cx_arl_remove(list, i, 1, NULL);
             }
@@ -1058,11 +926,11 @@
 }
 
 static void cx_arl_sort(struct cx_list_s *list) {
-    assert(list->collection.cmpfunc != NULL);
-    qsort(((cx_array_list *) list)->data,
+    cx_array_qsort_c(((cx_array_list *) list)->data,
           list->collection.size,
           list->collection.elem_size,
-          list->collection.cmpfunc
+          cx_list_compare_wrapper,
+          list
     );
 }
 
@@ -1070,12 +938,11 @@
         const struct cx_list_s *list,
         const struct cx_list_s *other
 ) {
-    assert(list->collection.cmpfunc != NULL);
     if (list->collection.size == other->collection.size) {
         const char *left = ((const cx_array_list *) list)->data;
         const char *right = ((const cx_array_list *) other)->data;
         for (size_t i = 0; i < list->collection.size; i++) {
-            int d = list->collection.cmpfunc(left, right);
+            int d = cx_list_compare_wrapper(left, right, (void*)list);
             if (d != 0) {
                 return d;
             }
@@ -1137,6 +1004,14 @@
     }
 }
 
+static int cx_arl_change_capacity(
+        struct cx_list_s *list,
+        size_t new_capacity
+) {
+    cx_array_list *arl = (cx_array_list *)list;
+    return cxReallocateArray(list->collection.allocator,
+        &arl->data, new_capacity, list->collection.elem_size);
+}
 
 static struct cx_iterator_s cx_arl_iterator(
         const struct cx_list_s *list,
@@ -1174,12 +1049,12 @@
         cx_arl_sort,
         cx_arl_compare,
         cx_arl_reverse,
+        cx_arl_change_capacity,
         cx_arl_iterator,
 };
 
 CxList *cxArrayListCreate(
         const CxAllocator *allocator,
-        cx_compare_func comparator,
         size_t elem_size,
         size_t initial_capacity
 ) {
@@ -1190,7 +1065,7 @@
     cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
     if (list == NULL) return NULL;
     cx_list_init((CxList*)list, &cx_array_list_class,
-        allocator, comparator, elem_size);
+        allocator, elem_size);
     list->capacity = initial_capacity;
 
     // allocate the array after the real elem_size is known
@@ -1201,8 +1076,5 @@
         return NULL;
     } // LCOV_EXCL_STOP
 
-    // configure the reallocator
-    list->reallocator = cx_array_reallocator(allocator, NULL);
-
     return (CxList *) list;
 }
--- a/ucx/buffer.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/buffer.c	Fri Dec 19 17:53:18 2025 +0100
@@ -32,28 +32,10 @@
 #include <string.h>
 #include <errno.h>
 
-#ifdef _WIN32
-#include <Windows.h>
-#include <sysinfoapi.h>
-static unsigned long system_page_size() {
-    static unsigned long ps = 0;
-    if (ps == 0) {
-        SYSTEM_INFO sysinfo;
-        GetSystemInfo(&sysinfo);
-        ps = sysinfo.dwPageSize;
-    }
-    return ps;
-}
-#define SYSTEM_PAGE_SIZE system_page_size()
-#else
-#include <unistd.h>
-#define SYSTEM_PAGE_SIZE sysconf(_SC_PAGESIZE)
-#endif
-
 static int buffer_copy_on_write(CxBuffer* buffer) {
     if (0 == (buffer->flags & CX_BUFFER_COPY_ON_WRITE)) return 0;
     void *newspace = cxMalloc(buffer->allocator, buffer->capacity);
-    if (NULL == newspace) return -1;
+    if (NULL == newspace) return -1;  // LCOV_EXCL_LINE
     memcpy(newspace, buffer->space, buffer->size);
     buffer->space = newspace;
     buffer->flags &= ~CX_BUFFER_COPY_ON_WRITE;
@@ -63,11 +45,11 @@
 
 int cxBufferInit(
         CxBuffer *buffer,
+        const CxAllocator *allocator,
         void *space,
         size_t capacity,
-        const CxAllocator *allocator,
         int flags
-) {
+        ) {
     if (allocator == NULL) {
         allocator = cxDefaultAllocator;
     }
@@ -78,52 +60,39 @@
     buffer->flags = flags;
     if (!space) {
         buffer->bytes = cxMalloc(allocator, capacity);
-        if (buffer->bytes == NULL) {
-            return -1; // LCOV_EXCL_LINE
-        }
+        if (buffer->bytes == NULL) return -1; // LCOV_EXCL_LINE
         buffer->flags |= CX_BUFFER_FREE_CONTENTS;
     } else {
         buffer->bytes = space;
     }
     buffer->capacity = capacity;
+    buffer->max_capacity = SIZE_MAX;
     buffer->size = 0;
     buffer->pos = 0;
 
-    buffer->flush = NULL;
-
-    return 0;
-}
-
-int cxBufferEnableFlushing(
-    CxBuffer *buffer,
-    CxBufferFlushConfig config
-) {
-    buffer->flush = cxMallocDefault(sizeof(CxBufferFlushConfig));
-    if (buffer->flush == NULL) return -1; // LCOV_EXCL_LINE
-    memcpy(buffer->flush, &config, sizeof(CxBufferFlushConfig));
     return 0;
 }
 
 void cxBufferDestroy(CxBuffer *buffer) {
-    if (buffer->flags & CX_BUFFER_FREE_CONTENTS) {
+    if ((buffer->flags & (CX_BUFFER_FREE_CONTENTS | CX_BUFFER_DO_NOT_FREE))
+            == CX_BUFFER_FREE_CONTENTS) {
         cxFree(buffer->allocator, buffer->bytes);
     }
-    cxFreeDefault(buffer->flush);
     memset(buffer, 0, sizeof(CxBuffer));
 }
 
 CxBuffer *cxBufferCreate(
+        const CxAllocator *allocator,
         void *space,
         size_t capacity,
-        const CxAllocator *allocator,
         int flags
-) {
+        ) {
     if (allocator == NULL) {
         allocator = cxDefaultAllocator;
     }
     CxBuffer *buf = cxMalloc(allocator, sizeof(CxBuffer));
-    if (buf == NULL) return NULL;
-    if (0 == cxBufferInit(buf, space, capacity, allocator, flags)) {
+    if (buf == NULL) return NULL; // LCOV_EXCL_LINE
+    if (0 == cxBufferInit(buf, allocator, space, capacity, flags)) {
         return buf;
     } else {
         // LCOV_EXCL_START
@@ -183,6 +152,35 @@
 
 }
 
+size_t cxBufferPop(CxBuffer *buffer, size_t size, size_t nitems) {
+    size_t len;
+    if (cx_szmul(size, nitems, &len)) {
+        // LCOV_EXCL_START
+        errno = EOVERFLOW;
+        return 0;
+        // LCOV_EXCL_STOP
+    }
+    if (len == 0) return 0;
+    if (len > buffer->size) {
+        if (size == 1) {
+            // simple case: everything can be discarded
+            len = buffer->size;
+        } else {
+            // complicated case: misaligned bytes must stay
+            size_t misalignment = buffer->size % size;
+            len = buffer->size - misalignment;
+        }
+    }
+    buffer->size -= len;
+
+    // adjust position, if required
+    if (buffer->pos > buffer->size) {
+        buffer->pos = buffer->size;
+    }
+
+    return len / size;
+}
+
 void cxBufferClear(CxBuffer *buffer) {
     if (0 == (buffer->flags & CX_BUFFER_COPY_ON_WRITE)) {
         memset(buffer->bytes, 0, buffer->size);
@@ -200,36 +198,13 @@
     return buffer->pos >= buffer->size;
 }
 
-int cxBufferMinimumCapacity(
-        CxBuffer *buffer,
-        size_t newcap
-) {
-    if (newcap <= buffer->capacity) {
+int cxBufferReserve(CxBuffer *buffer, size_t newcap) {
+    if (newcap == buffer->capacity) {
         return 0;
     }
-
-    unsigned long pagesize = SYSTEM_PAGE_SIZE;
-    // if page size is larger than 64 KB - for some reason - truncate to 64 KB
-    if (pagesize > 65536) pagesize = 65536;
-    if (newcap < pagesize) {
-        // when smaller as one page, map to the next power of two
-        newcap--;
-        newcap |= newcap >> 1;
-        newcap |= newcap >> 2;
-        newcap |= newcap >> 4;
-        // last operation only needed for pages larger 4096 bytes
-        // but if/else would be more expensive than just doing this
-        newcap |= newcap >> 8;
-        newcap++;
-    } else {
-        // otherwise, map to a multiple of the page size
-        newcap -= newcap % pagesize;
-        newcap += pagesize;
-        // note: if newcap is already page aligned,
-        // this gives a full additional page (which is good)
+    if (newcap > buffer->max_capacity) {
+        return -1;
     }
-
-
     const int force_copy_flags = CX_BUFFER_COPY_ON_WRITE | CX_BUFFER_COPY_ON_EXTEND;
     if (buffer->flags & force_copy_flags) {
         void *newspace = cxMalloc(buffer->allocator, newcap);
@@ -242,13 +217,60 @@
         return 0;
     } else if (cxReallocate(buffer->allocator,
                      (void **) &buffer->bytes, newcap) == 0) {
+        buffer->flags |= CX_BUFFER_FREE_CONTENTS;
         buffer->capacity = newcap;
+        if (buffer->size > newcap) {
+            buffer->size = newcap;
+        }
         return 0;
     } else {
         return -1; // LCOV_EXCL_LINE
     }
 }
 
+int cxBufferMaximumCapacity(CxBuffer *buffer, size_t capacity) {
+    if (capacity < buffer->capacity) {
+        return -1;
+    }
+    buffer->max_capacity = capacity;
+    return 0;
+}
+
+int cxBufferMinimumCapacity(CxBuffer *buffer, size_t newcap) {
+    if (newcap <= buffer->capacity) {
+        return 0;
+    }
+    if (newcap > buffer->max_capacity) {
+        return -1;
+    }
+    if (newcap < buffer->max_capacity) {
+        unsigned long pagesize = cx_system_page_size();
+        // if page size is larger than 64 KB - for some reason - truncate to 64 KB
+        if (pagesize > 65536) pagesize = 65536;
+        if (newcap < pagesize) {
+            // when smaller as one page, map to the next power of two
+            newcap--;
+            newcap |= newcap >> 1;
+            newcap |= newcap >> 2;
+            newcap |= newcap >> 4;
+            // last operation only needed for pages larger 4096 bytes
+            // but if/else would be more expensive than just doing this
+            newcap |= newcap >> 8;
+            newcap++;
+        } else {
+            // otherwise, map to a multiple of the page size
+            newcap -= newcap % pagesize;
+            newcap += pagesize;
+            // note: if newcap is already page aligned,
+            // this gives a full additional page (which is good)
+        }
+        if (newcap > buffer->max_capacity) {
+            newcap = buffer->max_capacity;
+        }
+    }
+    return cxBufferReserve(buffer, newcap);
+}
+
 void cxBufferShrink(
         CxBuffer *buffer,
         size_t reserve
@@ -271,60 +293,15 @@
     }
 }
 
-static size_t cx_buffer_flush_helper(
-        const CxBuffer *buffer,
-        const unsigned char *src,
-        size_t size,
-        size_t nitems
-) {
-    // flush data from an arbitrary source
-    // does not need to be the buffer's contents
-    size_t max_items = buffer->flush->blksize / size;
-    size_t fblocks = 0;
-    size_t flushed_total = 0;
-    while (nitems > 0 && fblocks < buffer->flush->blkmax) {
-        fblocks++;
-        size_t items = nitems > max_items ? max_items : nitems;
-        size_t flushed = buffer->flush->wfunc(
-            src, size, items, buffer->flush->target);
-        if (flushed > 0) {
-            flushed_total += flushed;
-            src += flushed * size;
-            nitems -= flushed;
-        } else {
-            // if no bytes can be flushed out anymore, we give up
-            break;
-        }
-    }
-    return flushed_total;
-}
-
-static size_t cx_buffer_flush_impl(CxBuffer *buffer, size_t size) {
-    // flush the current contents of the buffer
-    unsigned char *space = buffer->bytes;
-    size_t remaining = buffer->pos / size;
-    size_t flushed_total = cx_buffer_flush_helper(
-        buffer, space, size, remaining);
-
-    // shift the buffer left after flushing
-    // IMPORTANT: up to this point, copy on write must have been
-    // performed already, because we can't do error handling here
-    cxBufferShiftLeft(buffer, flushed_total*size);
-
-    return flushed_total;
-}
-
-size_t cxBufferFlush(CxBuffer *buffer) {
-    if (buffer_copy_on_write(buffer)) return 0;
-    return cx_buffer_flush_impl(buffer, 1);
-}
-
 size_t cxBufferWrite(
         const void *ptr,
         size_t size,
         size_t nitems,
         CxBuffer *buffer
 ) {
+    // trivial case
+    if (size == 0 || nitems == 0) return 0;
+
     // optimize for easy case
     if (size == 1 && (buffer->capacity - buffer->pos) >= nitems) {
         if (buffer_copy_on_write(buffer)) return 0;
@@ -336,98 +313,52 @@
         return nitems;
     }
 
-    size_t len, total_flushed = 0;
-cx_buffer_write_retry:
+    size_t len;
     if (cx_szmul(size, nitems, &len)) {
         errno = EOVERFLOW;
-        return total_flushed;
+        return 0;
     }
     if (buffer->pos > SIZE_MAX - len) {
         errno = EOVERFLOW;
-        return total_flushed;
+        return 0;
     }
+    const size_t required = buffer->pos + len;
 
-    size_t required = buffer->pos + len;
-    bool perform_flush = false;
+    // check if we need to auto-extend
     if (required > buffer->capacity) {
         if (buffer->flags & CX_BUFFER_AUTO_EXTEND) {
-            if (buffer->flush != NULL && required > buffer->flush->threshold) {
-                perform_flush = true;
-            } else {
-                if (cxBufferMinimumCapacity(buffer, required)) {
-                    return total_flushed; // LCOV_EXCL_LINE
-                }
-            }
-        } else {
-            if (buffer->flush != NULL) {
-                perform_flush = true;
-            } else {
-                // truncate data, if we can neither extend nor flush
-                len = buffer->capacity - buffer->pos;
-                if (size > 1) {
-                    len -= len % size;
-                }
-                nitems = len / size;
+            size_t newcap = required < buffer->max_capacity
+                    ? required : buffer->max_capacity;
+            if (cxBufferMinimumCapacity(buffer, newcap)) {
+                return 0; // LCOV_EXCL_LINE
             }
         }
     }
 
+    // check again and truncate data if capacity is still not enough
+    if (required > buffer->capacity) {
+        len = buffer->capacity - buffer->pos;
+        if (size > 1) {
+            len -= len % size;
+        }
+        nitems = len / size;
+    }
+
     // check here and not above because of possible truncation
     if (len == 0) {
-        return total_flushed;
+        return 0;
     }
 
     // check if we need to copy
     if (buffer_copy_on_write(buffer)) return 0;
 
     // perform the operation
-    if (perform_flush) {
-        size_t items_flushed;
-        if (buffer->pos == 0) {
-            // if we don't have data in the buffer, but are instructed
-            // to flush, it means that we are supposed to relay the data
-            items_flushed = cx_buffer_flush_helper(buffer, ptr, size, nitems);
-            if (items_flushed == 0) {
-                // we needed to relay data, but could not flush anything
-                // i.e. we have to give up to avoid endless trying
-                return 0;
-            }
-            nitems -= items_flushed;
-            total_flushed += items_flushed;
-            if (nitems > 0) {
-                ptr = ((unsigned char*)ptr) + items_flushed * size;
-                goto cx_buffer_write_retry;
-            }
-            return total_flushed;
-        } else {
-            items_flushed = cx_buffer_flush_impl(buffer, size);
-            if (items_flushed == 0) {
-                // flush target is full, let's try to truncate
-                size_t remaining_space;
-                if (buffer->flags & CX_BUFFER_AUTO_EXTEND) {
-                    remaining_space = buffer->flush->threshold > buffer->pos
-                                          ? buffer->flush->threshold - buffer->pos
-                                          : 0;
-                } else {
-                    remaining_space = buffer->capacity > buffer->pos
-                                          ? buffer->capacity - buffer->pos
-                                          : 0;
-                }
-                nitems = remaining_space / size;
-                if (nitems == 0) {
-                    return total_flushed;
-                }
-            }
-            goto cx_buffer_write_retry;
-        }
-    } else {
-        memcpy(buffer->bytes + buffer->pos, ptr, len);
-        buffer->pos += len;
-        if (buffer->pos > buffer->size) {
-            buffer->size = buffer->pos;
-        }
-        return total_flushed + nitems;
+    memcpy(buffer->bytes + buffer->pos, ptr, len);
+    buffer->pos += len;
+    if (buffer->pos > buffer->size) {
+        buffer->size = buffer->pos;
     }
+    return nitems;
 }
 
 size_t cxBufferAppend(
@@ -436,20 +367,13 @@
         size_t nitems,
         CxBuffer *buffer
 ) {
-    size_t pos = buffer->pos;
-    size_t append_pos = buffer->size;
-    buffer->pos = append_pos;    
-    size_t written = cxBufferWrite(ptr, size, nitems, buffer);
-    // the buffer might have been flushed
-    // we must compute a possible delta for the position
-    // expected: pos = append_pos + written
-    // -> if this is not the case, there is a delta
-    size_t delta = append_pos + written*size - buffer->pos;
-    if (delta > pos) {
-        buffer->pos = 0;
-    } else {
-        buffer->pos = pos - delta;
-    }
+    // trivial case
+    if (size == 0 || nitems == 0) return 0;
+
+    const size_t pos = buffer->pos;
+    buffer->pos = buffer->size;
+    const size_t written = cxBufferWrite(ptr, size, nitems, buffer);
+    buffer->pos = pos;
     return written;
 }
 
@@ -467,19 +391,35 @@
 }
 
 int cxBufferTerminate(CxBuffer *buffer) {
-    if (0 == cxBufferPut(buffer, 0)) {
-        buffer->size = buffer->pos - 1;
-        return 0;
+    // try to extend / shrink the buffer
+    if (buffer->pos >= buffer->capacity) {
+        if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == 0) {
+            return -1;
+        }
+        if (cxBufferReserve(buffer, buffer->pos + 1)) {
+            return -1; // LCOV_EXCL_LINE
+        }
     } else {
-        return -1;
+        buffer->size = buffer->pos;
+        cxBufferShrink(buffer, 1);
+        // set the capacity explicitly, in case shrink was skipped due to CoW
+        buffer->capacity = buffer->size + 1;
     }
+
+    // check if we are still on read-only memory
+    if (buffer_copy_on_write(buffer)) return -1;
+
+    // write the terminator and exit
+    buffer->space[buffer->pos] = '\0';
+    return 0;
 }
 
-size_t cxBufferPutString(
-        CxBuffer *buffer,
-        const char *str
-) {
-    return cxBufferWrite(str, 1, strlen(str), buffer);
+size_t cx_buffer_put_string(CxBuffer *buffer, cxstring str) {
+    return cxBufferWrite(str.ptr, 1, str.length, buffer);
+}
+
+size_t cx_buffer_append_string(CxBuffer *buffer, cxstring str) {
+    return cxBufferAppend(str.ptr, 1, str.length, buffer);
 }
 
 size_t cxBufferRead(
--- a/ucx/compare.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/compare.c	Fri Dec 19 17:53:18 2025 +0100
@@ -29,6 +29,7 @@
 #include "cx/compare.h"
 
 #include <math.h>
+#include <string.h>
 
 int cx_vcmp_int(int a, int b) {
     if (a == b) {
@@ -289,3 +290,21 @@
         return p1 < p2 ? -1 : 1;
     }
 }
+
+int cx_ccmp_memcmp(
+        const void *ptr1,
+        const void *ptr2,
+        void *size
+) {
+    size_t n = *(size_t*)size;
+    return memcmp(ptr1, ptr2, n);
+}
+
+int cx_ccmp_wrap(
+        const void *ptr1,
+        const void *ptr2,
+        void *w
+) {
+    cx_compare_func_wrapper *wrapper = w;
+    return wrapper->cmp(ptr1, ptr2);
+}
--- a/ucx/cx/allocator.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/allocator.h	Fri Dec 19 17:53:18 2025 +0100
@@ -142,17 +142,24 @@
  * @return either the specified @p target, a pointer to the allocated memory,
  * or @c NULL, if any error occurred
  */
-typedef void*(cx_clone_func)(void *target, const void *source,
+typedef void*(*cx_clone_func)(void *target, const void *source,
                              const CxAllocator *allocator, void *data);
 
 /**
- * Reallocate a previously allocated block and changes the pointer in-place,
- * if necessary.
+ * Returns the system's memory page size.
+ *
+ * If the page size cannot be retrieved from the system,
+ * a default of 4096 bytes is assumed.
  *
- * @note This will use stdlib reallocate and @em not the cxDefaultAllocator.
+ * @return the system's memory page size in bytes
+ */
+cx_attr_nodiscard
+CX_EXPORT unsigned long cx_system_page_size(void);
+
+/**
+ * Reallocate a previously allocated block.
  *
- * @par Error handling
- * @c errno will be set by realloc() on failure.
+ * Internal function - do not use.
  *
  * @param mem pointer to the pointer to allocated block
  * @param n the new size in bytes
@@ -164,16 +171,9 @@
 CX_EXPORT int cx_reallocate_(void **mem, size_t n);
 
 /**
- * Reallocate a previously allocated block and changes the pointer in-place,
- * if necessary.
- *
- * The size is calculated by multiplying @p nemb and @p size.
+ * Reallocate a previously allocated block.
  *
- * @note This will use stdlib reallocate and @em not the cxDefaultAllocator.
- *
- * @par Error handling
- * @c errno will be set by realloc() on failure or when the multiplication of
- * @p nmemb and @p size overflows.
+ * Internal function - do not use.
  *
  * @param mem pointer to the pointer to allocated block
  * @param nmemb the number of elements
@@ -261,6 +261,8 @@
  *
  * @note Re-allocating a block allocated by a different allocator is undefined.
  *
+ * @attention This function is bug-prone. Consider using cxReallocate().
+ *
  * @param allocator the allocator
  * @param mem pointer to the previously allocated block
  * @param n the new size in bytes
@@ -271,8 +273,8 @@
 CX_EXPORT void *cxRealloc(const CxAllocator *allocator, void *mem, size_t n);
 
 /**
- * Reallocate the previously allocated block in @p mem, making the new block
- * @p n bytes long.
+ * Reallocate the previously allocated block in @p mem.
+ *
  * This function may return the same pointer passed to it if moving
  * the memory was not necessary.
  *
@@ -282,6 +284,8 @@
  *
  * @note Re-allocating a block allocated by a different allocator is undefined.
  *
+ * @attention This function is bug-prone. Consider using cxReallocateArray().
+ *
  * @param allocator the allocator
  * @param mem pointer to the previously allocated block
  * @param nmemb the number of elements
@@ -294,14 +298,9 @@
         void *mem, size_t nmemb, size_t size);
 
 /**
- * Reallocate a previously allocated block and changes the pointer in-place,
- * if necessary.
- * This function acts like cxRealloc() using the pointer pointed to by @p mem.
+ * Reallocate a previously allocated block.
  *
- * @note Re-allocating a block allocated by a different allocator is undefined.
- *
- * @par Error handling
- * @c errno will be set if the underlying realloc function does so.
+ * Internal function - do not use.
  *
  * @param allocator the allocator
  * @param mem pointer to the pointer to allocated block
@@ -332,16 +331,9 @@
     cxReallocate_(allocator, (void**)(mem), n)
 
 /**
- * Reallocate a previously allocated block and changes the pointer in-place,
- * if necessary.
- * This function acts like cxReallocArray() using the pointer pointed to
- * by @p mem.
+ * Reallocate a previously allocated block.
  *
- * @note Re-allocating a block allocated by a different allocator is undefined.
- *
- * @par Error handling
- * @c errno will be set, if the underlying realloc function does so or the
- * multiplication of @p nmemb and @p size overflows.
+ * Internal function - do not use.
  *
  * @param allocator the allocator
  * @param mem pointer to the pointer to allocated block
@@ -377,7 +369,7 @@
         cxReallocateArray_(allocator, (void**) (mem), nmemb, size)
 
 /**
- * Allocate @p nmemb elements of @p n bytes each, all initialized to zero.
+ * Allocate @p nmemb elements of @p size bytes each, all initialized to zero.
  *
  * @param allocator the allocator
  * @param nmemb the number of elements
@@ -400,37 +392,125 @@
 CX_EXPORT void *cxZalloc(const CxAllocator *allocator, size_t n);
 
 /**
+ * Allocate @p n bytes of memory.
+ *
  * Convenience macro that invokes cxMalloc() with the cxDefaultAllocator.
+ *
+ * @param n (@c size_t) the number of bytes
+ * @return (@c void*) a pointer to the allocated memory
  */
-#define cxMallocDefault(...) cxMalloc(cxDefaultAllocator, __VA_ARGS__)
+#define cxMallocDefault(n) cxMalloc(cxDefaultAllocator, n)
+
 /**
+ * Allocate @p n bytes of memory and sets every byte to zero.
+ *
  * Convenience macro that invokes cxZalloc() with the cxDefaultAllocator.
+ *
+ * @param n (@c size_t) the number of bytes
+ * @return (@c void*) a pointer to the allocated memory
  */
-#define cxZallocDefault(...) cxZalloc(cxDefaultAllocator, __VA_ARGS__)
+#define cxZallocDefault(n) cxZalloc(cxDefaultAllocator, n)
+
 /**
+ * Allocate @p nmemb elements of @p size bytes each, all initialized to zero.
+ *
  * Convenience macro that invokes cxCalloc() with the cxDefaultAllocator.
+ *
+ * @param nmemb (@c size_t) the number of elements
+ * @param size (@c size_t) the size of each element in bytes
+ * @return (@c void*) a pointer to the allocated memory
  */
-#define cxCallocDefault(...) cxCalloc(cxDefaultAllocator, __VA_ARGS__)
+#define cxCallocDefault(nmemb, size) cxCalloc(cxDefaultAllocator, nmemb, size)
+
 /**
+ * Reallocate the previously allocated block in @p mem.
+ *
+ * This function may return the same pointer passed to it if moving
+ * the memory was not necessary.
+ *
  * Convenience macro that invokes cxRealloc() with the cxDefaultAllocator.
+ *
+ * @attention This function is bug-prone. Consider using cxReallocateDefault().
+ *
+ * @param mem (@c void*) pointer to the previously allocated block
+ * @param n (@c size_t) the new size in bytes
+ * @return (@c void*) a pointer to the reallocated memory
  */
-#define cxReallocDefault(...) cxRealloc(cxDefaultAllocator, __VA_ARGS__)
+#define cxReallocDefault(mem, n) cxRealloc(cxDefaultAllocator, mem, n)
+
 /**
+ * Reallocate a previously allocated block and changes the pointer in-place,
+ * if necessary.
+ * This function acts like cxRealloc() using the pointer pointed to by @p mem.
+ *
  * Convenience macro that invokes cxReallocate() with the cxDefaultAllocator.
+ *
+ * @note Re-allocating a block allocated by a different allocator is undefined.
+ *
+ * @par Error handling
+ * @c errno will be set if the underlying realloc function does so.
+ *
+ * @param mem (@c void**) pointer to the pointer to allocated block
+ * @param n (@c size_t) the new size in bytes
+ * @retval zero success
+ * @retval non-zero failure
  */
-#define cxReallocateDefault(...) cxReallocate(cxDefaultAllocator, __VA_ARGS__)
-/**
- * Convenience macro that invokes cxReallocateArray() with the cxDefaultAllocator.
- */
-#define cxReallocateArrayDefault(...) cxReallocateArray(cxDefaultAllocator, __VA_ARGS__)
+#define cxReallocateDefault(mem, n) cxReallocate(cxDefaultAllocator, mem, n)
+
 /**
- * Convenience macro that invokes cxReallocArray() with the cxDefaultAllocator.
+ * Reallocate a previously allocated block and changes the pointer in-place,
+ * if necessary.
+ * This function acts like cxReallocArray() using the pointer pointed to
+ * by @p mem.
+ *
+ * Convenience macro that invokes cxReallocateArray() with the cxDefaultAllocator.
+ *
+ * @note Re-allocating a block allocated by a different allocator is undefined.
+ *
+ * @par Error handling
+ * @c errno will be set, if the underlying realloc function does so or the
+ * multiplication of @p nmemb and @p size overflows.
+ *
+ * @param mem (@c void**) pointer to the pointer to allocated block
+ * @param nmemb (@c size_t) the number of elements
+ * @param size (@c size_t) the size of each element
+ * @retval zero success
+ * @retval non-zero failure
  */
-#define cxReallocArrayDefault(...) cxReallocArray(cxDefaultAllocator, __VA_ARGS__)
+#define cxReallocateArrayDefault(mem, nmemb, size) \
+        cxReallocateArray(cxDefaultAllocator, mem, nmemb, size)
+
 /**
- * Convenience macro that invokes cxFree() with the cxDefaultAllocator.
+ * Reallocate the previously allocated block in @p mem.
+ *
+ * Convenience macro that invokes cxReallocArray() with the cxDefaultAllocator.
+ *
+ * This function may return the same pointer passed to it if moving
+ * the memory was not necessary.
+ *
+ * The size is calculated by multiplying @p nemb and @p size.
+ * If that multiplication overflows, this function returns @c NULL, and @c errno
+ * will be set.
+ *
+ * @note Re-allocating a block allocated by a different allocator is undefined.
+ *
+ * @attention This function is bug-prone. Consider using cxReallocateArrayDefault().
+ *
+ * @param mem (@c void*) pointer to the previously allocated block
+ * @param nmemb (@c size_t) the number of elements
+ * @param size (@c size_t) the size of each element
+ * @return (@c void*) a pointer to the reallocated memory
  */
-#define cxFreeDefault(...) cxFree(cxDefaultAllocator, __VA_ARGS__)
+#define cxReallocArrayDefault(mem, nmemb, size) cxReallocArray(cxDefaultAllocator, mem, nmemb, size)
+
+/**
+ * Free a block of memory.
+ *
+ * Convenience function that invokes cxFree() with the cxDefaultAllocator.
+ *
+ * @param mem the memory to deallocate
+ */
+CX_EXPORT void cxFreeDefault(void *mem);
 
 #ifdef __cplusplus
 } // extern "C"
--- a/ucx/cx/array_list.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/array_list.h	Fri Dec 19 17:53:18 2025 +0100
@@ -50,617 +50,892 @@
 CX_EXPORT extern const unsigned cx_array_swap_sbo_size;
 
 /**
- * Declares variables for an array that can be used with the convenience macros.
- *
- * @par Examples
- * @code
- * // integer array with at most 255 elements
- * CX_ARRAY_DECLARE_SIZED(int, myarray, uint8_t)
+ * Declares a typed array with size and capacity.
  *
- * // array of MyObject* pointers where size and capacity are stored as unsigned int
- * CX_ARRAY_DECLARE_SIZED(MyObject*, objects, unsigned int)
- *
- * // initializing code
- * cx_array_initialize(myarray, 16); // reserve space for 16
- * cx_array_initialize(objects, 100); // reserve space for 100
- * @endcode
+ * @param type the type of the elements
+ * @param name the name of the array
+ */
+#define CX_ARRAY(type, name) \
+    struct { \
+        type *data; \
+        size_t size; \
+        size_t capacity; \
+    } name
+
+/**
+ * Internal structure for arrays.
  *
- * @param type the type of the data
- * @param name the name of the array
- * @param size_type the type of the size (should be uint8_t, uint16_t, uint32_t, or size_t)
+ * A generalization of array structures declared with CX_ARRAY().
+ */
+typedef struct cx_array_s {
+    /** The array data. */
+    void *data;
+    /** The number of elements. */
+    size_t size;
+    /** The maximum number of elements. */
+    size_t capacity;
+} CxArray;
+
+/**
+ * Initializes an array by allocating memory.
  *
- * @see cx_array_initialize()
- * @see cx_array_simple_add()
- * @see cx_array_simple_copy()
- * @see cx_array_simple_add_sorted()
- * @see cx_array_simple_insert_sorted()
+ * Internal function - do not use manually.
+ *
+ * @param allocator the allocator for the array
+ * @param array a pointer to the array structure
+ * @param elem_size size of one element
+ * @param capacity the initial maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
  */
-#define CX_ARRAY_DECLARE_SIZED(type, name, size_type) \
-    type * name; \
-    /** Array size. */ size_type name##_size; \
-    /** Array capacity. */ size_type name##_capacity
+cx_attr_nonnull
+CX_EXPORT int cx_array_init_(const CxAllocator *allocator, CxArray *array, size_t elem_size, size_t capacity);
 
 /**
- * Declares variables for an array that can be used with the convenience macros.
- *
- * The size and capacity variables will have type @c size_t.
- * Use #CX_ARRAY_DECLARE_SIZED() to specify a different type.
+ * Initializes an array by allocating memory.
  *
- * @par Examples
- * @code
- * // int array
- * CX_ARRAY_DECLARE(int, myarray)
+ * The size is set to zero.
+ *
+ * @attention If the array was already initialized, this will leak memory.
+ * Use cx_array_reserve() to change the capacity of an initialized array.
  *
- * // initializing code
- * cx_array_initialize(myarray, 32); // reserve space for 32
- * @endcode
- *
- * @param type the type of the data
- * @param name the name of the array
- *
- * @see cx_array_initialize()
- * @see cx_array_simple_add()
- * @see cx_array_simple_copy()
- * @see cx_array_simple_add_sorted()
- * @see cx_array_simple_insert_sorted()
+ * @param allocator (@c CxAllocator*) the allocator for the array
+ * @param array the name of the array
+ * @param capacity (@c size_t) the initial maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
  */
-#define CX_ARRAY_DECLARE(type, name) CX_ARRAY_DECLARE_SIZED(type, name, size_t)
+#define cx_array_init_a(allocator, array, capacity) cx_array_init_(allocator, (CxArray*)&(array), sizeof((array).data[0]), capacity)
 
 /**
- * Initializes an array with the given capacity.
- *
- * The type of the capacity depends on the type used during declaration.
+ * Initializes an array by allocating memory.
  *
- * @par Examples
- * @code
- * CX_ARRAY_DECLARE_SIZED(int, arr1, uint8_t)
- * CX_ARRAY_DECLARE(int, arr2) // size and capacity are implicitly size_t
+ * The size is set to zero.
  *
- * // initializing code
- * cx_array_initialize(arr1, 500); // error: maximum for uint8_t is 255
- * cx_array_initialize(arr2, 500); // OK
- * @endcode
- *
- *
- * The memory for the array is allocated with the cxDefaultAllocator.
+ * @attention If the array was already initialized, this will leak memory.
  *
  * @param array the name of the array
- * @param capacity the initial capacity
- * @see cx_array_initialize_a()
- * @see CX_ARRAY_DECLARE_SIZED()
- * @see CX_ARRAY_DECLARE()
+ * @param capacity (@c size_t) the initial maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
  */
-#define cx_array_initialize(array, capacity) \
-        array##_capacity = capacity; \
-        array##_size = 0; \
-        array = cxMallocDefault(sizeof(array[0]) * capacity)
+#define cx_array_init(array, capacity) cx_array_init_a(cxDefaultAllocator, array, capacity)
+
+/**
+ * Initializes an array with fixed size memory.
+ *
+ * Internal function - do not use manually.
+ *
+ * @param array a pointer to the array structure
+ * @param data the fixed size array
+ * @param capacity the capacity of the fixed size array
+ * @param size the number of initialized elements in the fixed size array
+ */
+cx_attr_nonnull
+CX_EXPORT void cx_array_init_fixed_(CxArray *array, const void *data, size_t capacity, size_t size);
 
 /**
- * Initializes an array with the given capacity using the specified allocator.
+ * Initializes an array with fixed size memory.
+ *
+ * This is useful, for example, when you want to work with memory on the stack
+ * and only want to move to the heap when the stack memory is not enough.
+ *
+ * With the @p num_initialized argument you can specify how many elements in the
+ * fixed size array are already correctly initialized, which determines the
+ * initial size of the array.
  *
- * @par Example
- * @code
- * CX_ARRAY_DECLARE(int, myarray)
+ * The capacity is determined automatically by the compiler.
  *
+ * @attention When you add elements to an array that was initialized with fixed
+ * size memory, you MUST check the capacity before adding the element and invoke
+ * cx_array_copy_to_new() when you intend to exceed the capacity.
+ *
+ * @attention When you pass a pointer to an array that does not have a fixed
+ * size, the behavior is unspecified.
  *
- * const CxAllocator *al = // ...
- * cx_array_initialize_a(al, myarray, 128);
- * // ...
- * cxFree(al, myarray); // remember to free with the same allocator
- * @endcode
+ * @param array the name of the array to initialize
+ * @param fixed_size_array (@c void*) the fixed size array
+ * @param num_initialized (@c size_t) the number of already initialized elements in the fixed size array
+ * @see cx_array_copy_to_new()
+ */
+#define cx_array_init_fixed(array, fixed_size_array, num_initialized) \
+        cx_array_init_fixed_((CxArray*)&(array), fixed_size_array, cx_nmemb(fixed_size_array), num_initialized)
+
+/**
+ * Changes the capacity of an array.
  *
- * @param allocator (@c CxAllocator*) the allocator
- * @param array the name of the array
- * @param capacity the initial capacity
- * @see cx_array_initialize()
- * @see CX_ARRAY_DECLARE_SIZED()
- * @see CX_ARRAY_DECLARE()
+ * Internal function - do not use.
+ *
+ * @param allocator the allocator
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @param capacity the new capacity
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
  */
-#define cx_array_initialize_a(allocator, array, capacity) \
-        array##_capacity = capacity; \
-        array##_size = 0; \
-        array = cxMalloc(allocator, sizeof(array[0]) * capacity)
+cx_attr_nonnull
+CX_EXPORT int cx_array_reserve_(const CxAllocator *allocator, CxArray *array, size_t elem_size, size_t capacity);
 
 /**
- * Defines a reallocation mechanism for arrays.
- * You can create your own, use cx_array_reallocator(), or
- * use the #cx_array_default_reallocator.
+ * Changes the capacity of an array.
+ *
+ * If required, the size is reduced to fit into the new capacity.
+ *
+ * @param allocator (@c CxAllocator*) the allocator for the array
+ * @param array the name of the array
+ * @param capacity (@c size_t) the new maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
  */
-struct cx_array_reallocator_s {
-    /**
-     * Reallocates space for the given array.
-     *
-     * Implementations are not required to free the original array.
-     * This allows reallocation of static or stack memory by allocating heap memory
-     * and copying the array contents; namely when @c stack_ptr in this struct
-     * is not @c NULL and @p array equals @c stack_ptr.
-     *
-     * @param array the array to reallocate
-     * @param old_capacity the old number of elements
-     * @param new_capacity the new number of elements
-     * @param elem_size the size of each element
-     * @param alloc a reference to this allocator
-     * @return a pointer to the reallocated memory or @c NULL on failure
-     */
-    void *(*realloc)( void *array, size_t old_capacity, size_t new_capacity,
-            size_t elem_size, struct cx_array_reallocator_s *alloc);
+#define cx_array_reserve_a(allocator, array, capacity) \
+        cx_array_reserve_(allocator, (CxArray*)&(array), sizeof((array).data[0]), capacity)
 
-    /**
-     * The allocator that shall be used for the reallocations.
-     */
-    const CxAllocator *allocator;
-    /**
-     * Optional pointer to stack memory
-     * if the array is originally located on the stack.
-     */
-    const void *stack_ptr;
-};
+/**
+ * Changes the capacity of an array.
+ *
+ * If required, the size is reduced to fit into the new capacity.
+ *
+ * @param array the name of the array
+ * @param capacity (@c size_t) the new maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
+ */
+#define cx_array_reserve(array, capacity) \
+        cx_array_reserve_a(cxDefaultAllocator, array, capacity)
 
 /**
- * Typedef for the array reallocator struct.
+ * Copies the array to a new memory region.
+ *
+ * Internal function - do not use.
+ *
+ * @param allocator the allocator for new new memory
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @param capacity the new capacity
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
  */
-typedef struct cx_array_reallocator_s CxArrayReallocator;
-
-/**
- * A default array reallocator that is based on the cxDefaultAllocator.
- */
-CX_EXPORT extern CxArrayReallocator *cx_array_default_reallocator;
+cx_attr_nonnull
+CX_EXPORT int cx_array_copy_to_new_(const CxAllocator *allocator, CxArray *array, size_t elem_size, size_t capacity);
 
 /**
- * Creates a new array reallocator.
- *
- * When @p allocator is @c NULL, the cxDefaultAllocator will be used.
+ * Copies the array to a new memory region.
  *
- * When @p stack_ptr is not @c NULL, the reallocator is supposed to be used
- * @em only for the specific array initially located at @p stack_ptr.
- * When reallocation is needed, the reallocator checks if the array is
- * still located at @p stack_ptr and copies the contents to the heap.
+ * This is useful when you have initialized the array with a fixed size memory
+ * using cx_array_init_fixed(), and now you want to increase the capacity.
+ *
+ * @attention When the original memory does not belong to stack memory, and
+ * you do not have another reference to this memory, it will leak.
  *
- * @note Invoking this function with both arguments being @c NULL will return a
- * reallocator that behaves like #cx_array_default_reallocator.
- *
- * @param allocator the allocator this reallocator shall be based on
- * @param stack_ptr the address of the array when the array is initially located
- * on the stack or shall not reallocate in place
- * @return an array reallocator
+ * @param allocator (@c CxAllocator*) the allocator for the new memory
+ * @param array the name of the array
+ * @param capacity (@c size_t) the new maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
+ * @see cx_array_init_fixed()
  */
-CX_EXPORT CxArrayReallocator cx_array_reallocator(
-        const struct cx_allocator_s *allocator, const void *stack_ptr);
+#define cx_array_copy_to_new_a(allocator, array, capacity) \
+        cx_array_copy_to_new_(allocator, (CxArray*)&(array), sizeof((array).data[0]), capacity)
 
 /**
- * Reserves memory for additional elements.
- *
- * This function checks if the @p capacity of the array is sufficient to hold
- * at least @p size plus @p elem_count elements. If not, a reallocation is
- * performed with the specified @p reallocator.
- * You can create your own reallocator by hand, use #cx_array_default_reallocator,
- * or use the convenience function cx_array_reallocator() to create a custom reallocator.
+ * Copies the array to a new memory region.
  *
- * This function can be useful to replace subsequent calls to cx_array_copy()
- * with one single cx_array_reserve() and then - after guaranteeing a
- * sufficient capacity - use simple memmove() or memcpy().
+ * This is useful when you have initialized the array with a fixed size memory
+ * using cx_array_init_fixed(), and now you want to increase the capacity.
  *
- * The @p width in bytes refers to the size and capacity.
- * Both must have the same width.
- * Supported are 0, 1, 2, and 4, as well as 8 if running on a 64-bit
- * architecture. If set to zero, the native word width is used.
+ * @attention When the original memory does not belong to stack memory, and
+ * you do not have another reference to this memory, it will leak.
  *
- * @param array a pointer to the target array
- * @param size a pointer to the size of the array
- * @param capacity a pointer to the capacity of the array
- * @param width the width in bytes for the @p size and @p capacity or zero for default
+ * @param array the name of the array
+ * @param capacity (@c size_t) the new maximum number of elements
+ * @retval zero allocation was successful
+ * @retval non-zero allocation failed
+ * @see cx_array_init_fixed()
+ */
+#define cx_array_copy_to_new(array, capacity) \
+        cx_array_copy_to_new_a(cxDefaultAllocator, array, capacity)
+
+/**
+ * Inserts data into an array.
+ *
+ * Internal function - do not use.
+ *
+ * @param allocator the allocator to use for a possible reallocation
+ * @param array a pointer to the array structure
  * @param elem_size the size of one element
- * @param elem_count the number of expected additional elements
- * @param reallocator the array reallocator to use
- * (@c NULL defaults to #cx_array_default_reallocator)
+ * @param index the index where to insert the @p other data
+ * @param other a pointer to an array of data that shall be inserted
+ * @param n the number of elements that shall be inserted
  * @retval zero success
- * @retval non-zero failure
- * @see cx_array_reallocator()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-cx_attr_nonnull_arg(1, 2, 3)
-CX_EXPORT int cx_array_reserve(void **array, void *size, void *capacity,
-        unsigned width, size_t elem_size, size_t elem_count,
-        CxArrayReallocator *reallocator);
+cx_attr_nonnull_arg(1, 2)
+CX_EXPORT int cx_array_insert_(const CxAllocator *allocator, CxArray *array,
+        size_t elem_size, size_t index, const void *other, size_t n);
 
 /**
- * Copies elements from one array to another.
- *
- * The elements are copied to the @p target array at the specified @p index,
- * overwriting possible elements. The @p index does not need to be in range of
- * the current array @p size. If the new index plus the number of elements added
- * extends the array's size, the remaining @p capacity is used.
+ * Appends an element to an array.
  *
- * If the @p capacity is also insufficient to hold the new data, a reallocation
- * attempt is made with the specified @p reallocator.
- * You can create your own reallocator by hand, use #cx_array_default_reallocator,
- * or use the convenience function cx_array_reallocator() to create a custom reallocator.
- *
- * The @p width in bytes refers to the size and capacity.
- * Both must have the same width.
- * Supported are 0, 1, 2, and 4, as well as 8 if running on a 64-bit
- * architecture. If set to zero, the native word width is used.
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
  *
- * @param target a pointer to the target array
- * @param size a pointer to the size of the target array
- * @param capacity a pointer to the capacity of the target array
- * @param width the width in bytes for the @p size and @p capacity or zero for default
- * @param index the index where the copied elements shall be placed
- * @param src the source array
- * @param elem_size the size of one element
- * @param elem_count the number of elements to copy
- * @param reallocator the array reallocator to use
- * (@c NULL defaults to #cx_array_default_reallocator)
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the element shall be added
+ * @param element the element that shall be added
  * @retval zero success
- * @retval non-zero failure
- * @see cx_array_reallocator()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-cx_attr_nonnull_arg(1, 2, 3, 6)
-CX_EXPORT int cx_array_copy(void **target, void *size, void *capacity, unsigned width,
-        size_t index, const void *src, size_t elem_size, size_t elem_count,
-        CxArrayReallocator *reallocator);
+#define cx_array_add_a(allocator, array, element) \
+        cx_array_insert_(allocator, (CxArray*)&(array), sizeof((array).data[0]), (array).size, (void*)&(element), 1)
+
+/**
+ * Appends an element to an array.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @param array the name of the array where the element shall be added
+ * @param element (@c void*) a pointer to the element that shall be added
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_add(array, element) \
+        cx_array_add_a(cxDefaultAllocator, array, element)
 
 /**
- * Convenience macro that uses cx_array_copy() with a default layout and
- * the specified reallocator.
+ * Inserts an element into an array.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param index (@c size_t) the index where the copied elements shall be placed
- * @param src (@c void*) the source array
- * @param count (@c size_t) the number of elements to copy
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the element shall be inserted
+ * @param index (@c size_t) the index where to insert the @p element
+ * @param element the element that shall be inserted
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_copy()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_copy_a(reallocator, array, index, src, count) \
-    cx_array_copy((void**)&(array), &(array##_size), &(array##_capacity), \
-        sizeof(array##_size), index, src, sizeof((array)[0]), count, \
-        reallocator)
+#define cx_array_insert_a(allocator, array, index, element) \
+        cx_array_insert_(allocator, (CxArray*)&(array), sizeof((array).data[0]), index, (void*)&(element), 1)
 
 /**
- * Convenience macro that uses cx_array_copy() with a default layout and
- * the default reallocator.
+ * Inserts an element into an array.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
  *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param index (@c size_t) the index where the copied elements shall be placed
- * @param src (@c void*) the source array
- * @param count (@c size_t) the number of elements to copy
+ * @param array the name of the array where the element shall be inserted
+ * @param index (@c size_t) the index where to insert the @p element
+ * @param element (@c void*) a pointer to the element that shall be inserted
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_copy_a()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_copy(array, index, src, count) \
-    cx_array_simple_copy_a(NULL, array, index, src, count)
+#define cx_array_insert(array, index, element) \
+        cx_array_insert_a(cxDefaultAllocator, array, index, element)
 
 /**
- * Convenience macro that uses cx_array_reserve() with a default layout and
- * the specified reallocator.
+ * Inserts data into an array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param count (@c size_t) the number of expected @em additional elements
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param index (@c size_t) the index where to insert the @p other data
+ * @param other (@c void*) a pointer to an array of data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_reserve()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_reserve_a(reallocator, array, count) \
-    cx_array_reserve((void**)&(array), &(array##_size), &(array##_capacity), \
-        sizeof(array##_size), sizeof((array)[0]), count, \
-        reallocator)
+#define cx_array_insert_array_a(allocator, array, index, other, n) \
+        cx_array_insert_(allocator, (CxArray*)&(array), sizeof((array).data[0]), index, other, n)
 
 /**
- * Convenience macro that uses cx_array_reserve() with a default layout and
- * the default reallocator.
+ * Inserts data into an array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
  *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param count (@c size_t) the number of expected additional elements
+ * @param array the name of the array where the elements shall be inserted
+ * @param index (@c size_t) the index where to insert the @p other data
+ * @param other (@c void*) a pointer to an array of data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_reserve_a()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_reserve(array, count) \
-    cx_array_simple_reserve_a(NULL, array, count)
+#define cx_array_insert_array(array, index, other, n) \
+        cx_array_insert_array_a(cxDefaultAllocator, array, index, other, n)
+
+/**
+ * Appends data to an array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be added
+ * @param other (@c void*) a pointer to an array of data that shall be added
+ * @param n (@c size_t) the number of elements that shall be added
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_add_array_a(allocator, array, other, n) \
+        cx_array_insert_(allocator, (CxArray*)&(array), sizeof((array).data[0]), (array).size, other, n)
 
 /**
- * Adds an element to an array with the possibility of allocating more space.
- *
- * The element @p elem is added to the end of the @p target array which contains
- * @p size elements, already. The @p capacity must point to a variable denoting
- * the current maximum number of elements the array can hold.
+ * Appends data to an array.
  *
- * If the capacity is insufficient to hold the new element, an attempt to
- * increase the @p capacity is made and the new capacity is written back.
- *
- * The \@ SIZE_TYPE is flexible and can be any unsigned integer type.
- * It is important, however, that @p size and @p capacity are pointers to
- * variables of the same type.
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
  *
- * @param target (@c void**) a pointer to the target array
- * @param size (@c SIZE_TYPE*) a pointer to the size of the target array
- * @param capacity (@c SIZE_TYPE*) a pointer to the capacity of the target array
- * @param elem_size (@c size_t) the size of one element
- * @param elem (@c void*) a pointer to the element to add
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
+ * @param array the name of the array where the elements shall be added
+ * @param other (@c void*) a pointer to an array of data that shall be added
+ * @param n (@c size_t) the number of elements that shall be added
  * @retval zero success
- * @retval non-zero failure
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_add(target, size, capacity, elem_size, elem, reallocator) \
-    cx_array_copy((void**)(target), size, capacity, sizeof(*(size)), \
-    *(size), elem, elem_size, 1, reallocator)
+#define cx_array_add_array(array, other, n) \
+        cx_array_add_array_a(cxDefaultAllocator, array, other, n)
 
 /**
- * Convenience macro that uses cx_array_add() with a default layout and
- * the specified reallocator.
+ * Inserts sorted data into a sorted array.
+ *
+ * Internal function - do not use.
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param elem the element to add (NOT a pointer, address is automatically taken)
+ * @param allocator the allocator to use for a possible reallocation
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @param sorted_data a pointer to an array of data that shall be inserted
+ * @param n the number of elements that shall be inserted
+ * @param cmp_func the compare function
+ * @param allow_duplicates @c false if duplicates shall be skipped during insertion
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_add()
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_add_a(reallocator, array, elem) \
-    cx_array_simple_copy_a(reallocator, array, array##_size, &(elem), 1)
+cx_attr_nonnull
+CX_EXPORT int cx_array_insert_sorted_(const CxAllocator *allocator, CxArray *array,
+        size_t elem_size, const void *sorted_data, size_t n,
+        cx_compare_func cmp_func, bool allow_duplicates);
 
 /**
- * Convenience macro that uses cx_array_add() with a default layout and
- * the default reallocator.
+ * Inserts an element into a sorted array.
  *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param elem the element to add (NOT a pointer, address is automatically taken)
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_add_a()
- */
-#define cx_array_simple_add(array, elem) \
-    cx_array_simple_add_a(cx_array_default_reallocator, array, elem)
-
-/**
- * Inserts a sorted array into another sorted array.
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
  *
- * If either the target or the source array is not already sorted with respect
- * to the specified @p cmp_func, the behavior is undefined.
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
  *
- * If the capacity is insufficient to hold the new data, a reallocation
- * attempt is made.
- * You can create your own reallocator by hand, use #cx_array_default_reallocator,
- * or use the convenience function cx_array_reallocator() to create a custom reallocator.
- *
- * @param target a pointer to the target array
- * @param size a pointer to the size of the target array
- * @param capacity a pointer to the capacity of the target array
- * @param cmp_func the compare function for the elements
- * @param src the source array
- * @param elem_size the size of one element
- * @param elem_count the number of elements to insert
- * @param reallocator the array reallocator to use
- * (@c NULL defaults to #cx_array_default_reallocator)
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
  * @retval zero success
- * @retval non-zero failure
+ * @retval non-zero a re-allocation was necessary but failed
  */
-cx_attr_nonnull_arg(1, 2, 3, 5)
-CX_EXPORT int cx_array_insert_sorted(void **target, size_t *size, size_t *capacity,
-        cx_compare_func cmp_func, const void *src, size_t elem_size, size_t elem_count,
-        CxArrayReallocator *reallocator);
+#define cx_array_insert_sorted_a(allocator, array, element, cmp_func) \
+        cx_array_insert_sorted_(allocator, (CxArray*)&(array), sizeof((array).data[0]), (void*)&(element), 1, cmp_func, true)
 
 /**
  * Inserts an element into a sorted array.
  *
- * If the target array is not already sorted with respect
- * to the specified @p cmp_func, the behavior is undefined.
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_sorted(array, element, cmp_func) \
+        cx_array_insert_sorted_a(cxDefaultAllocator, array, element, cmp_func)
+
+/**
+ * Inserts sorted data into a sorted array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
  *
- * If the capacity is not enough to hold the new data, a reallocation
- * attempt is made.
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
  *
- * The \@ SIZE_TYPE is flexible and can be any unsigned integer type.
- * It is important, however, that @p size and @p capacity are pointers to
- * variables of the same type.
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_sorted_array_a(allocator, array, sorted_data, n, cmp_func) \
+        cx_array_insert_sorted_(allocator, (CxArray*)&(array), sizeof((array).data[0]), sorted_data, n, cmp_func, true)
+
+/**
+ * Inserts sorted data into a sorted array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
  *
- * @param target (@c void**) a pointer to the target array
- * @param size (@c SIZE_TYPE*) a pointer to the size of the target array
- * @param capacity (@c SIZE_TYPE*) a pointer to the capacity of the target array
- * @param elem_size (@c size_t) the size of one element
- * @param elem (@c void*) a pointer to the element to add
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
  * @retval zero success
- * @retval non-zero failure
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_sorted_array(array, sorted_data, n, cmp_func) \
+        cx_array_insert_sorted_array_a(cxDefaultAllocator, array, sorted_data, n, cmp_func)
+
+/**
+ * Inserts an element into a sorted array if it is not already contained.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_add_sorted(target, size, capacity, elem_size, elem, cmp_func, reallocator) \
-    cx_array_insert_sorted((void**)(target), size, capacity, cmp_func, elem, elem_size, 1, reallocator)
+#define cx_array_insert_unique_a(allocator, array, element, cmp_func) \
+        cx_array_insert_sorted_(allocator, (CxArray*)&(array), sizeof((array).data[0]), (void*)&(element), 1, cmp_func, false)
+
+/**
+ * Inserts an element into a sorted array if it is not already contained.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_unique(array, element, cmp_func) \
+        cx_array_insert_unique_a(cxDefaultAllocator, array, element, cmp_func)
 
 /**
- * Convenience macro for cx_array_add_sorted() with a default
- * layout and the specified reallocator.
+ * Inserts sorted data into a sorted array, skipping duplicates.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_unique_array_a(allocator, array, sorted_data, n, cmp_func) \
+        cx_array_insert_sorted_(allocator, (CxArray*)&(array), sizeof((array).data[0]), sorted_data, n, cmp_func, false)
+
+/**
+ * Inserts sorted data into a sorted array, skipping duplicates.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param elem the element to add (NOT a pointer, address is automatically taken)
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func) the compare function that establishes the order
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_unique_array(array, sorted_data, n, cmp_func) \
+        cx_array_insert_unique_array_a(cxDefaultAllocator, array, sorted_data, n, cmp_func)
+
+/**
+ * Inserts sorted data into a sorted array.
+ *
+ * Internal function - do not use.
+ *
+ * @param allocator the allocator to use for a possible reallocation
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @param sorted_data a pointer to an array of data that shall be inserted
+ * @param n the number of elements that shall be inserted
+ * @param cmp_func the compare function
+ * @param context additional context for the compare function
+ * @param allow_duplicates @c false if duplicates shall be skipped during insertion
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_add_sorted()
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+cx_attr_nonnull_arg(1, 2, 4, 6)
+CX_EXPORT int cx_array_insert_sorted_c_(const CxAllocator *allocator, CxArray *array,
+        size_t elem_size, const void *sorted_data, size_t n,
+        cx_compare_func2 cmp_func, void *context, bool allow_duplicates);
+
+/**
+ * Inserts an element into a sorted array.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_add_sorted_a(reallocator, array, elem, cmp_func) \
-    cx_array_add_sorted(&array, &(array##_size), &(array##_capacity), \
-        sizeof((array)[0]), &(elem), cmp_func, reallocator)
+#define cx_array_insert_sorted_ca(allocator, array, element, cmp_func) \
+        cx_array_insert_sorted_c_(allocator, (CxArray*)&(array), sizeof((array).data[0]), (void*)&(element), 1, cmp_func, context, true)
+
+/**
+ * Inserts an element into a sorted array.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_sorted_c(array, element, cmp_func, context) \
+        cx_array_insert_sorted_ca(cxDefaultAllocator, array, element, cmp_func, context)
+
+/**
+ * Inserts sorted data into a sorted array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_sorted_array_ca(allocator, array, sorted_data, n, cmp_func, context) \
+        cx_array_insert_sorted_c_(allocator, (CxArray*)&(array), sizeof((array).data[0]), sorted_data, n, cmp_func, context, true)
 
 /**
- * Convenience macro for cx_array_add_sorted() with a default
- * layout and the default reallocator.
+ * Inserts sorted data into a sorted array.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
  *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param elem the element to add (NOT a pointer, address is automatically taken)
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_sorted_array_c(array, sorted_data, n, cmp_func, context) \
+        cx_array_insert_sorted_array_ca(cxDefaultAllocator, array, sorted_data, n, cmp_func, context)
+
+/**
+ * Inserts an element into a sorted array if it is not already contained.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
  * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_add_sorted_a()
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_unique_ca(allocator, array, element, cmp_func, context) \
+        cx_array_insert_sorted_c_(allocator, (CxArray*)&(array), sizeof((array).data[0]), (void*)&(element), 1, cmp_func, context, false)
+
+/**
+ * Inserts an element into a sorted array if it is not already contained.
+ *
+ * When the capacity is not enough to hold the new element, a re-allocation is attempted.
+ *
+ * @attention if the array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param array the name of the array where the elements shall be inserted
+ * @param element the element that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
  */
-#define cx_array_simple_add_sorted(array, elem, cmp_func) \
-    cx_array_simple_add_sorted_a(NULL, array, elem, cmp_func)
+#define cx_array_insert_unique_c(array, element, cmp_func, context) \
+        cx_array_insert_unique_ca(cxDefaultAllocator, array, element, cmp_func, context)
+
+/**
+ * Inserts sorted data into a sorted array, skipping duplicates.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param allocator (@c CxAllocator*) the allocator to use for a possible reallocation
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_unique_array_ca(allocator, array, sorted_data, n, cmp_func, context) \
+        cx_array_insert_sorted_c_(allocator, (CxArray*)&(array), sizeof((array).data[0]), sorted_data, n, cmp_func, context, false)
+
+/**
+ * Inserts sorted data into a sorted array, skipping duplicates.
+ *
+ * When the capacity is not enough to hold the new elements, a re-allocation is attempted.
+ *
+ * @attention if either array is not sorted according to the specified @p cmp_func, the behavior is undefined.
+ *
+ * @param array the name of the array where the elements shall be inserted
+ * @param sorted_data (@c void*) a pointer to an array of sorted data that shall be inserted
+ * @param n (@c size_t) the number of elements that shall be inserted
+ * @param cmp_func (@c cx_compare_func2) the compare function that establishes the order
+ * @param context (@c void*) additional context for the compare function
+ * @retval zero success
+ * @retval non-zero a re-allocation was necessary but failed
+ */
+#define cx_array_insert_unique_array_c(array, sorted_data, n, cmp_func, context) \
+        cx_array_insert_unique_array_ca(cxDefaultAllocator, array, sorted_data, n, cmp_func, context)
 
 /**
- * Convenience macro for cx_array_insert_sorted() with a default
- * layout and the specified reallocator.
+ * An alternative to qsort_r() when that is not available on your platform.
+ *
+ * If it is available, qsort_r() is used directly.
+ *
+ * @param array the array that shall be sorted
+ * @param nmemb the number of elements in the array
+ * @param size the size of one element
+ * @param fn the compare function
+ * @param context the context for the compare function
+ */
+CX_EXPORT void cx_array_qsort_c(void *array, size_t nmemb, size_t size,
+        cx_compare_func2 fn, void *context);
+
+/**
+ * Sorts an array.
+ *
+ * Internal function - do not use.
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param src (@c void*) pointer to the source array
- * @param n (@c size_t) number of elements in the source array
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_insert_sorted()
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @param fn the compare function
  */
-#define cx_array_simple_insert_sorted_a(reallocator, array, src, n, cmp_func) \
-    cx_array_insert_sorted((void**)(&array), &(array##_size), &(array##_capacity), \
-        cmp_func, src, sizeof((array)[0]), n, reallocator)
+CX_EXPORT void cx_array_sort_(CxArray *array, size_t elem_size,
+        cx_compare_func fn);
+
+/**
+ * Sorts an array.
+ *
+ * Internal function - do not use.
+ *
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @param fn the compare function
+ * @param context the context for the compare function
+ */
+CX_EXPORT void cx_array_sort_c_(CxArray *array, size_t elem_size,
+        cx_compare_func2 fn, void *context);
+
+/**
+ * Sorts an array.
+ *
+ * @param array the name of the array
+ * @param fn (@c cx_compare_func) the compare function
+ * @param context (@c void*) the context for the compare function
+ */
+#define cx_array_sort(array, fn) \
+        cx_array_sort_((CxArray*)&(array), sizeof((array).data[0]), fn)
 
 /**
- * Convenience macro for cx_array_insert_sorted() with a default
- * layout and the default reallocator.
+ * Sorts an array.
+ *
+ * @param array the name of the array
+ * @param fn (@c cx_compare_func2) the compare function
+ * @param context (@c void*) the context for the compare function
+ */
+#define cx_array_sort_c(array, fn, context) \
+        cx_array_sort_c_((CxArray*)&(array), sizeof((array).data[0]), fn, context)
+
+/**
+ * Creates an iterator over the elements of an array.
+ *
+ * Internal function - do not use.
+ *
+ * @param array a pointer to the array structure
+ * @param elem_size the size of one element
+ * @return an iterator over the elements
+ */
+cx_attr_nodiscard cx_attr_nonnull
+CX_EXPORT CxIterator cx_array_iterator_(CxArray *array, size_t elem_size);
+
+/**
+ * Creates an iterator over the elements of an array.
+ *
+ * The iterator will yield pointers to the elements.
+ *
+ * This iterator cannot be used to remove elements
+ * because it does not get a modifiable reference to the array's size.
  *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param src (@c void*) pointer to the source array
- * @param n (@c size_t) number of elements in the source array
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_insert_sorted_a()
+ * @param array the name of the array
+ * @return an iterator over the elements
+ * @see cx_array_iterator_ptr()
+ */
+#define cx_array_iterator(array) \
+        cx_array_iterator_((CxArray*)&(array), sizeof((array).data[0]))
+
+/**
+ * Creates an iterator over the elements of an array containing pointers.
+ *
+ * Internal function - do not use.
+ *
+ * @param array the name of the array
+ * @return an iterator over the elements
  */
-#define cx_array_simple_insert_sorted(array, src, n, cmp_func) \
-    cx_array_simple_insert_sorted_a(NULL, array, src, n, cmp_func)
+cx_attr_nodiscard cx_attr_nonnull
+CX_EXPORT CxIterator cx_array_iterator_ptr_(CxArray *array);
+
+/**
+ * Creates an iterator over the elements of an array containing pointers.
+ *
+ * The iterator will yield the elements themselves, which are supposed to
+ * be pointers.
+ *
+ * This iterator cannot be used to remove elements
+ * because it does not get a modifiable reference to the array's size.
+ *
+ * @param array the name of the array
+ * @return an iterator over the elements
+ * @see cx_array_iterator()
+ */
+#define cx_array_iterator_ptr(array) \
+        cx_array_iterator_ptr_((CxArray*)&(array))
 
 
 /**
- * Inserts a sorted array into another sorted array, avoiding duplicates.
- *
- * If either the target or the source array is not already sorted with respect
- * to the specified @p cmp_func, the behavior is undefined.
+ * Removes elements from the array.
  *
- * If the capacity is insufficient to hold the new data, a reallocation
- * attempt is made.
- * You can create your own reallocator by hand, use #cx_array_default_reallocator,
- * or use the convenience function cx_array_reallocator() to create a custom reallocator.
+ * Internal function - do not use.
  *
- * @param target a pointer to the target array
- * @param size a pointer to the size of the target array
- * @param capacity a pointer to the capacity of the target array
- * @param cmp_func the compare function for the elements
- * @param src the source array
+ * @param array a pointer to the array structure
  * @param elem_size the size of one element
- * @param elem_count the number of elements to insert
- * @param reallocator the array reallocator to use
- * (@c NULL defaults to #cx_array_default_reallocator)
- * @retval zero success
- * @retval non-zero failure
+ * @param index the index of the first element to remove
+ * @param n the number of elements to remove
+ * @param fast indicates whether tail elements should be copied into the gap
  */
-cx_attr_nonnull_arg(1, 2, 3, 5)
-CX_EXPORT int cx_array_insert_unique(void **target, size_t *size, size_t *capacity,
-        cx_compare_func cmp_func, const void *src, size_t elem_size, size_t elem_count,
-        CxArrayReallocator *reallocator);
+cx_attr_nonnull
+CX_EXPORT void cx_array_remove_(CxArray *array, size_t elem_size, size_t index, size_t n, bool fast);
 
 /**
- * Inserts an element into a sorted array if it does not exist.
- *
- * If the target array is not already sorted with respect
- * to the specified @p cmp_func, the behavior is undefined.
+ * Removes one element from the array.
  *
- * If the capacity is insufficient to hold the new data, a reallocation
- * attempt is made.
+ * Tail elements are all moved by one. If you don't need a stable order
+ * in the array, consider using cx_array_remove_fast().
  *
- * The \@ SIZE_TYPE is flexible and can be any unsigned integer type.
- * It is important, however, that @p size and @p capacity are pointers to
- * variables of the same type.
+ * If the index is out of bounds, this function does nothing.
  *
- * @param target (@c void**) a pointer to the target array
- * @param size (@c SIZE_TYPE*) a pointer to the size of the target array
- * @param capacity (@c SIZE_TYPE*) a pointer to the capacity of the target array
- * @param elem_size (@c size_t) the size of one element
- * @param elem (@c void*) a pointer to the element to add
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @retval zero success (also when the element was already present)
- * @retval non-zero failure
+ * @param array the name of the array
+ * @param index (@c size_t) the index of the element to remove
+ * @see cx_array_remove_fast()
  */
-#define cx_array_add_unique(target, size, capacity, elem_size, elem, cmp_func, reallocator) \
-    cx_array_insert_unique((void**)(target), size, capacity, cmp_func, elem, elem_size, 1, reallocator)
+#define cx_array_remove(array, index) \
+        cx_array_remove_((CxArray*)&(array), sizeof((array).data[0]), index, 1, false)
+
+/**
+ * Removes one element from the array.
+ *
+ * The gap will be filled with a copy of the last element in the array.
+ * This changes the order of elements. If you want a stable order,
+ * use cx_array_remove() instead.
+ *
+ * If the index is out of bounds, this function does nothing.
+ *
+ * @param array the name of the array
+ * @param index (@c size_t) the index of the element to remove
+ * @see cx_array_remove()
+ */
+#define cx_array_remove_fast(array, index) \
+        cx_array_remove_((CxArray*)&(array), sizeof((array).data[0]), index, 1, true)
 
 /**
- * Convenience macro for cx_array_add_unique() with a default
- * layout and the specified reallocator.
+ * Removes multiple elements from the array.
+ *
+ * Tail elements are all moved to close the gap. If you don't need a stable
+ * order in the array, consider using cx_array_remove_array_fast().
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param elem the element to add (NOT a pointer, address is automatically taken)
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_add_unique()
+ * If the index is out of bounds, this function does nothing.
+ * If @n overflows the array, this function removes as many elements as it can.
+ *
+ * @param array the name of the array
+ * @param index (@c size_t) the index of the first element to remove
+ * @param n (@c size_t) the number of elements to remove
+ * @see cx_array_remove_array_fast()
  */
-#define cx_array_simple_add_unique_a(reallocator, array, elem, cmp_func) \
-    cx_array_add_unique(&array, &(array##_size), &(array##_capacity), \
-        sizeof((array)[0]), &(elem), cmp_func, reallocator)
-
-/**
- * Convenience macro for cx_array_add_unique() with a default
- * layout and the default reallocator.
- *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param elem the element to add (NOT a pointer, address is automatically taken)
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_add_unique_a()
- */
-#define cx_array_simple_add_unique(array, elem, cmp_func) \
-    cx_array_simple_add_unique_a(NULL, array, elem, cmp_func)
+#define cx_array_remove_array(array, index, n) \
+        cx_array_remove_((CxArray*)&(array), sizeof((array).data[0]), index, n, false)
 
 /**
- * Convenience macro for cx_array_insert_unique() with a default
- * layout and the specified reallocator.
+ * Removes multiple elements from the array.
+ *
+ * Tail elements are copied into the gap. If you have more tail elements
+ * than the number of elements that are removed, this will change the order
+ * of elements. If you want a stable order, use cx_array_remove_array() instead.
  *
- * @param reallocator (@c CxArrayReallocator*) the array reallocator to use
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param src (@c void*) pointer to the source array
- * @param n (@c size_t) number of elements in the source array
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_insert_unique()
+ * If the index is out of bounds, this function does nothing.
+ * If @n overflows the array, this function removes as many elements as it can.
+ *
+ * @param array the name of the array
+ * @param index (@c size_t) the index of the first element to remove
+ * @param n (@c size_t) the number of elements to remove
+ * @see cx_array_remove_array()
  */
-#define cx_array_simple_insert_unique_a(reallocator, array, src, n, cmp_func) \
-    cx_array_insert_unique((void**)(&array), &(array##_size), &(array##_capacity), \
-        cmp_func, src, sizeof((array)[0]), n, reallocator)
+#define cx_array_remove_array_fast(array, index, n) \
+        cx_array_remove_((CxArray*)&(array), sizeof((array).data[0]), index, n, true)
 
 /**
- * Convenience macro for cx_array_insert_unique() with a default
- * layout and the default reallocator.
+ * Deallocates an array.
+ *
+ * Internal function - do not use.
+ *
+ * @param allocator (@c CxAllocator*) the allocator which was used to allocate the array
+ * @param array a pointer to the array structure
+ */
+cx_attr_nonnull
+CX_EXPORT void cx_array_free_(const CxAllocator *allocator, CxArray *array);
+
+/**
+ * Deallocates an array.
+ *
+ * The structure is reset to zero and can be re-initialized with
+ * cx_array_inita().
  *
- * @param array the name of the array (NOT a pointer or alias to the array)
- * @param src (@c void*) pointer to the source array
- * @param n (@c size_t) number of elements in the source array
- * @param cmp_func (@c cx_cmp_func) the compare function for the elements
- * @retval zero success
- * @retval non-zero failure
- * @see CX_ARRAY_DECLARE()
- * @see cx_array_simple_insert_unique_a()
+ * @param array the name of the array
  */
-#define cx_array_simple_insert_unique(array, src, n, cmp_func) \
-    cx_array_simple_insert_unique_a(NULL, array, src, n, cmp_func)
+#define cx_array_free(array) cx_array_free_(cxDefaultAllocator, (CxArray*)&(array))
+
+/**
+ * Deallocates an array.
+ *
+ * The structure is reset to zero and can be re-initialized with
+ * cx_array_init_a().
+ *
+ * @param allocator (@c CxAllocator*) the allocator which was used to allocate the array
+ * @param array the name of the array
+ */
+#define cx_array_free_a(allocator, array) cx_array_free_(allocator, (CxArray*)&(array))
+
 
 /**
  * Searches the largest lower bound in a sorted array.
@@ -669,6 +944,9 @@
  * in @p arr that is less or equal to @p elem with respect to @p cmp_func.
  * When no such element exists, @p size is returned.
  *
+ * When such an element exists more than once, the largest index of all those
+ * elements is returned.
+ *
  * If @p elem is contained in the array, this is identical to
  * #cx_array_binary_search().
  *
@@ -691,6 +969,9 @@
 /**
  * Searches an item in a sorted array.
  *
+ * When such an element exists more than once, the largest index of all those
+ * elements is returned.
+ *
  * If the array is not sorted with respect to the @p cmp_func, the behavior
  * is undefined.
  *
@@ -715,6 +996,9 @@
  * in @p arr that is greater or equal to @p elem with respect to @p cmp_func.
  * When no such element exists, @p size is returned.
  *
+ * When such an element exists more than once, the smallest index of all those
+ * elements is returned.
+ *
  * If @p elem is contained in the array, this is identical to
  * #cx_array_binary_search().
  *
@@ -734,6 +1018,91 @@
 CX_EXPORT size_t cx_array_binary_search_sup(const void *arr, size_t size,
         size_t elem_size, const void *elem, cx_compare_func cmp_func);
 
+
+/**
+ * Searches the largest lower bound in a sorted array.
+ *
+ * In other words, this function returns the index of the largest element
+ * in @p arr that is less or equal to @p elem with respect to @p cmp_func.
+ * When no such element exists, @p size is returned.
+ *
+ * When such an element exists more than once, the largest index of all those
+ * elements is returned.
+ *
+ * If @p elem is contained in the array, this is identical to
+ * #cx_array_binary_search().
+ *
+ * If the array is not sorted with respect to the @p cmp_func, the behavior
+ * is undefined.
+ *
+ * @param arr the array to search
+ * @param size the size of the array
+ * @param elem_size the size of one element
+ * @param elem the element to find
+ * @param cmp_func the compare function
+ * @param context the context for the compare function
+ * @return the index of the largest lower bound, or @p size
+ * @see cx_array_binary_search_sup()
+ * @see cx_array_binary_search()
+ */
+cx_attr_nonnull
+CX_EXPORT size_t cx_array_binary_search_inf_c(const void *arr, size_t size,
+        size_t elem_size, const void *elem, cx_compare_func2 cmp_func, void *context);
+
+/**
+ * Searches an item in a sorted array.
+ *
+ * When such an element exists more than once, the largest index of all those
+ * elements is returned.
+ *
+ * If the array is not sorted with respect to the @p cmp_func, the behavior
+ * is undefined.
+ *
+ * @param arr the array to search
+ * @param size the size of the array
+ * @param elem_size the size of one element
+ * @param elem the element to find
+ * @param cmp_func the compare function
+ * @param context the context for the compare function
+ * @return the index of the element in the array, or @p size if the element
+ * cannot be found
+ * @see cx_array_binary_search_inf()
+ * @see cx_array_binary_search_sup()
+ */
+cx_attr_nonnull
+CX_EXPORT size_t cx_array_binary_search_c(const void *arr, size_t size,
+        size_t elem_size, const void *elem, cx_compare_func2 cmp_func, void *context);
+
+/**
+ * Searches the smallest upper bound in a sorted array.
+ *
+ * In other words, this function returns the index of the smallest element
+ * in @p arr that is greater or equal to @p elem with respect to @p cmp_func.
+ * When no such element exists, @p size is returned.
+ *
+ * When such an element exists more than once, the smallest index of all those
+ * elements is returned.
+ *
+ * If @p elem is contained in the array, this is identical to
+ * #cx_array_binary_search().
+ *
+ * If the array is not sorted with respect to the @p cmp_func, the behavior
+ * is undefined.
+ *
+ * @param arr the array to search
+ * @param size the size of the array
+ * @param elem_size the size of one element
+ * @param elem the element to find
+ * @param cmp_func the compare function
+ * @param context the context for the compare function
+ * @return the index of the smallest upper bound, or @p size
+ * @see cx_array_binary_search_inf()
+ * @see cx_array_binary_search()
+ */
+cx_attr_nonnull
+CX_EXPORT size_t cx_array_binary_search_sup_c(const void *arr, size_t size,
+        size_t elem_size, const void *elem, cx_compare_func2 cmp_func, void *context);
+
 /**
  * Swaps two array elements.
  *
@@ -750,13 +1119,10 @@
  *
  * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
  * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr(), if none is given.
+ * to cx_cmp_ptr().
  *
  * @param allocator the allocator for allocating the list memory
  * (if @c NULL, the cxDefaultAllocator will be used)
- * @param comparator the comparator for the elements
- * (if @c NULL, and the list is not storing pointers, sort and find
- * functions will not work)
  * @param elem_size the size of each element in bytes
  * @param initial_capacity the initial number of elements the array can store
  * @return the created list
@@ -765,25 +1131,7 @@
 cx_attr_malloc
 cx_attr_dealloc(cxListFree, 1)
 CX_EXPORT CxList *cxArrayListCreate(const CxAllocator *allocator,
-        cx_compare_func comparator, size_t elem_size, size_t initial_capacity);
-
-/**
- * Allocates an array list for storing elements with @p elem_size bytes each.
- *
- * The list will use the cxDefaultAllocator and @em NO compare function.
- * If you want to call functions that need a compare function, you have to
- * set it immediately after creation or use cxArrayListCreate().
- *
- * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
- * copies of the added elements and the compare function will be automatically set
- * to cx_cmp_ptr().
- *
- * @param elem_size (@c size_t) the size of each element in bytes
- * @param initial_capacity (@c size_t) the initial number of elements the array can store
- * @return the created list
- */
-#define cxArrayListCreateSimple(elem_size, initial_capacity) \
-    cxArrayListCreate(NULL, NULL, elem_size, initial_capacity)
+        size_t elem_size, size_t initial_capacity);
 
 #ifdef __cplusplus
 } // extern "C"
--- a/ucx/cx/buffer.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/buffer.h	Fri Dec 19 17:53:18 2025 +0100
@@ -48,6 +48,7 @@
 
 #include "common.h"
 #include "allocator.h"
+#include "string.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -89,6 +90,13 @@
 #define CX_BUFFER_COPY_ON_EXTEND 0x08
 
 /**
+ * If this flag is enabled, the buffer will never free its contents regardless of #CX_BUFFER_FREE_CONTENTS.
+ *
+ * This is useful, for example, when you want to keep a pointer to the data after destroying the buffer.
+ */
+#define CX_BUFFER_DO_NOT_FREE 0x10
+
+/**
  * Function pointer for cxBufferWrite that is compatible with cx_write_func.
  * @see cx_write_func
  */
@@ -99,59 +107,6 @@
  */
 #define cxBufferReadFunc  ((cx_read_func) cxBufferRead)
 
-/**
- * Configuration for automatic flushing.
- */
-struct cx_buffer_flush_config_s {
-    /**
-     * The buffer may not extend beyond this threshold before starting to flush.
-     *
-     * Only used when the buffer uses #CX_BUFFER_AUTO_EXTEND.
-     * The threshold will be the maximum capacity the buffer is extended to
-     * before flushing.
-     */
-    size_t threshold;
-    /**
-     * The block size for the elements to flush.
-     */
-    size_t blksize;
-    /**
-     * The maximum number of blocks to flush in one cycle.
-     *
-     * @attention while it is guaranteed that cxBufferFlush() will not flush
-     * more blocks, this is not necessarily the case for cxBufferWrite().
-     * After performing a flush cycle, cxBufferWrite() will retry the write
-     * operation and potentially trigger another flush cycle, until the
-     * flush target accepts no more data.
-     */
-    size_t blkmax;
-
-    /**
-     * The target for the write function.
-     */
-    void *target;
-
-    /**
-     * The write-function used for flushing.
-     * If NULL, the flushed content gets discarded.
-     */
-    cx_write_func wfunc;
-};
-
-/**
- * Type alias for the flush configuration struct.
- *
- * @code
- * struct cx_buffer_flush_config_s {
- *     size_t threshold;
- *     size_t blksize;
- *     size_t blkmax;
- *     void *target;
- *     cx_write_func wfunc;
- * };
- * @endcode
- */
-typedef struct cx_buffer_flush_config_s CxBufferFlushConfig;
 
 /** Structure for the UCX buffer data. */
 struct cx_buffer_s {
@@ -168,16 +123,12 @@
     };
     /** The allocator to use for automatic memory management. */
     const CxAllocator *allocator;
-    /**
-     * Optional flush configuration
-     *
-     * @see cxBufferEnableFlushing()
-     */
-    CxBufferFlushConfig *flush;
     /** Current position of the buffer. */
     size_t pos;
     /** Current capacity (i.e. maximum size) of the buffer. */
     size_t capacity;
+    /** Maximum capacity that this buffer may grow to. */
+    size_t max_capacity;
     /** Current size of the buffer content. */
     size_t size;
     /**
@@ -217,35 +168,18 @@
  * space will be leaking after the copy-on-write operation.
  *
  * @param buffer the buffer to initialize
+ * @param allocator the allocator this buffer shall use for automatic
+ * memory management
+ * (if @c NULL, the cxDefaultAllocator will be used)
  * @param space pointer to the memory area, or @c NULL to allocate
  * new memory
  * @param capacity the capacity of the buffer
- * @param allocator the allocator this buffer shall use for automatic
- * memory management
- * (if @c NULL, the cxDefaultAllocator will be used)
  * @param flags buffer features (see cx_buffer_s.flags)
  * @return zero on success, non-zero if a required allocation failed
  */
 cx_attr_nonnull_arg(1)
-CX_EXPORT int cxBufferInit(CxBuffer *buffer, void *space, size_t capacity,
-        const CxAllocator *allocator, int flags);
-
-/**
- * Configures the buffer for flushing.
- *
- * Flushing can happen automatically when data is written
- * to the buffer (see cxBufferWrite()) or manually when
- * cxBufferFlush() is called.
- *
- * @param buffer the buffer
- * @param config the flush configuration
- * @retval zero success
- * @retval non-zero failure
- * @see cxBufferFlush()
- * @see cxBufferWrite()
- */
-cx_attr_nonnull
-CX_EXPORT int cxBufferEnableFlushing(CxBuffer *buffer, CxBufferFlushConfig config);
+CX_EXPORT int cxBufferInit(CxBuffer *buffer, const CxAllocator *allocator,
+        void *space, size_t capacity, int flags);
 
 /**
  * Destroys the buffer contents.
@@ -285,18 +219,18 @@
  * Then this function will allocate the space and enforce
  * the #CX_BUFFER_FREE_CONTENTS flag.
  *
+ * @param allocator the allocator to use for allocating the structure and the automatic
+ * memory management within the buffer
+ * (if @c NULL, the cxDefaultAllocator will be used)
  * @param space pointer to the memory area, or @c NULL to allocate
  * new memory
  * @param capacity the capacity of the buffer
- * @param allocator the allocator to use for allocating the structure and the automatic
- * memory management within the buffer
- * (if @c NULL, the cxDefaultAllocator will be used)
  * @param flags buffer features (see cx_buffer_s.flags)
  * @return a pointer to the buffer on success, @c NULL if a required allocation failed
  */
 cx_attr_malloc cx_attr_dealloc(cxBufferFree, 1) cx_attr_nodiscard
-CX_EXPORT CxBuffer *cxBufferCreate(void *space, size_t capacity,
-        const CxAllocator *allocator, int flags);
+CX_EXPORT CxBuffer *cxBufferCreate(const CxAllocator *allocator, void *space,
+                                   size_t capacity, int flags);
 
 /**
  * Shifts the contents of the buffer by the given offset.
@@ -388,6 +322,20 @@
 CX_EXPORT int cxBufferSeek(CxBuffer *buffer, off_t offset, int whence);
 
 /**
+ * Discards items from the end of the buffer.
+ *
+ * When the current position points to a byte that gets discarded,
+ * the position is set to the buffer size.
+ *
+ * @param buffer the buffer
+ * @param size the size of one item
+ * @param nitems the number of items to discard
+ * @return the actual number of discarded items
+ */
+cx_attr_nonnull
+CX_EXPORT size_t cxBufferPop(CxBuffer *buffer, size_t size, size_t nitems);
+
+/**
  * Clears the buffer by resetting the position and deleting the data.
  *
  * The data is deleted by zeroing it with a call to memset().
@@ -425,11 +373,51 @@
 cx_attr_nonnull cx_attr_nodiscard
 CX_EXPORT bool cxBufferEof(const CxBuffer *buffer);
 
+/**
+ * Ensures that the buffer has the required capacity.
+ *
+ * If the current capacity is not sufficient, the buffer will be extended.
+ * If the current capacity is larger, the buffer is shrunk and superfluous
+ * content is discarded.
+ *
+ * This function will reserve no more bytes than requested, in contrast to
+ * cxBufferMinimumCapacity(), which may reserve more bytes to improve the
+ * number of future necessary reallocations.
+ *
+ * @param buffer the buffer
+ * @param capacity the required capacity for this buffer
+ * @retval zero on success
+ * @retval non-zero on allocation failure
+ * @see cxBufferShrink()
+ * @see cxBufferMinimumCapacity()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxBufferReserve(CxBuffer *buffer, size_t capacity);
+
+/**
+ * Limits the buffer's capacity.
+ *
+ * If the current capacity is already larger, this function fails and returns
+ * non-zero.
+ *
+ * The capacity limit will affect auto-extension features, as well as future
+ * calls to cxBufferMinimumCapacity() and cxBufferReserve().
+ *
+ * @param buffer the buffer
+ * @param capacity the maximum allowed capacity for this buffer
+ * @retval zero the limit is applied
+ * @retval non-zero the new limit is smaller than the current capacity
+ * @see cxBufferReserve()
+ * @see cxBufferMinimumCapacity()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxBufferMaximumCapacity(CxBuffer *buffer, size_t capacity);
 
 /**
  * Ensures that the buffer has a minimum capacity.
  *
- * If the current capacity is not sufficient, the buffer will be extended.
+ * If the current capacity is not sufficient, the buffer will be generously
+ * extended.
  *
  * The new capacity will be a power of two until the system's page size is reached.
  * Then, the new capacity will be a multiple of the page size.
@@ -438,6 +426,8 @@
  * @param capacity the minimum required capacity for this buffer
  * @retval zero the capacity was already sufficient or successfully increased
  * @retval non-zero on allocation failure
+ * @see cxBufferMaximumCapacity()
+ * @see cxBufferReserve()
  * @see cxBufferShrink()
  */
 cx_attr_nonnull
@@ -457,6 +447,7 @@
  *
  * @param buffer the buffer
  * @param reserve the number of bytes that shall remain reserved
+ * @see cxBufferReserve()
  * @see cxBufferMinimumCapacity()
  */
 cx_attr_nonnull
@@ -465,33 +456,13 @@
 /**
  * Writes data to a CxBuffer.
  *
- * If automatic flushing is not enabled, the data is simply written into the
- * buffer at the current position, and the position of the buffer is increased
- * by the number of bytes written.
- *
- * If flushing is enabled and the buffer needs to flush, the data is flushed to
- * the target until the target signals that it cannot take more data by
- * returning zero via the respective write function. In that case, the remaining
- * data in this buffer is shifted to the beginning of this buffer so that the
- * newly available space can be used to append as much data as possible.
- *
- * This function only stops writing more elements when the flush target and this
- * buffer are both incapable of taking more data or all data has been written.
+ * If auto-extension is enabled, the buffer's capacity is automatically
+ * increased when it is not large enough to hold all data.
+ * By default, the capacity grows indefinitely, unless limited with
+ * cxBufferMaximumCapacity().
+ * When auto-extension fails, this function writes no data and returns zero.
  *
- * If, after flushing, the number of items that shall be written still exceeds
- * the capacity or flush threshold, this function tries to write all items directly
- * to the flush target, if possible.
- *
- * The number returned by this function is the number of elements from
- * @c ptr that could be written to either the flush target or the buffer.
- * That means it does @em not include the number of items that were already in
- * the buffer and were also flushed during the process.
- *
- * @attention
- * When @p size is larger than one and the contents of the buffer are not aligned
- * with @p size, flushing stops after all complete items have been flushed, leaving
- * the misaligned part in the buffer.
- * Afterward, this function only writes as many items as possible to the buffer.
+ * The position of the buffer is moved alongside the written data.
  *
  * @note The signature is compatible with the fwrite() family of functions.
  *
@@ -531,62 +502,6 @@
         size_t nitems, CxBuffer *buffer);
 
 /**
- * Performs a single flush-run on the specified buffer.
- *
- * Does nothing when the position in the buffer is zero.
- * Otherwise, the data until the current position minus
- * one is considered for flushing.
- * Note carefully that flushing will never exceed the
- * current @em position, even when the size of the
- * buffer is larger than the current position.
- *
- * One flush run will try to flush @c blkmax many
- * blocks of size @c blksize until either the @p buffer
- * has no more data to flush or the write function
- * used for flushing returns zero.
- *
- * The buffer is shifted left for that many bytes
- * the flush operation has successfully flushed.
- *
- * @par Example 1
- * Assume you have a buffer with size 340 and you are
- * at position 200. The flush configuration is
- * @c blkmax=4 and @c blksize=64 .
- * Assume that the entire flush operation is successful.
- * All 200 bytes on the left-hand-side from the current
- * position are written.
- * That means the size of the buffer is now 140 and the
- * position is zero.
- *
- * @par Example 2
- * Same as Example 1, but now the @c blkmax is 1.
- * The size of the buffer is now 276, and the position is 136.
- *
- * @par Example 3
- * Same as Example 1, but now assume the flush target
- * only accepts 100 bytes before returning zero.
- * That means the flush operation manages to flush
- * one complete block and one partial block, ending
- * up with a buffer with size 240 and position 100.
- *
- * @remark Just returns zero when flushing was not enabled with
- * cxBufferEnableFlushing().
- *
- * @remark When the buffer uses copy-on-write, the memory
- * is copied first, before attempting any flush.
- * This is, however, considered an erroneous use of the
- * buffer because it makes little sense to put
- * readonly data into an UCX buffer for flushing instead
- * of writing it directly to the target.
- *
- * @param buffer the buffer
- * @return the number of successfully flushed bytes
- * @see cxBufferEnableFlushing()
- */
-cx_attr_nonnull
-CX_EXPORT size_t cxBufferFlush(CxBuffer *buffer);
-
-/**
  * Reads data from a CxBuffer.
  *
  * The position of the buffer is increased by the number of bytes read.
@@ -610,8 +525,9 @@
  *
  * The least significant byte of the argument is written to the buffer. If the
  * end of the buffer is reached and #CX_BUFFER_AUTO_EXTEND feature is enabled,
- * the buffer capacity is extended by cxBufferMinimumCapacity(). If the feature
- * is disabled or the buffer extension fails, @c EOF is returned.
+ * the buffer capacity is extended, unless a limit set by
+ * cxBufferMaximumCapacity() is reached.
+ * If the feature is disabled or the buffer extension fails, @c EOF is returned.
  *
  * On successful writing, the position of the buffer is increased.
  *
@@ -620,8 +536,8 @@
  *
  * @param buffer the buffer to write to
  * @param c the character to write
- * @return the byte that has been written or @c EOF when the end of the stream is
- * reached, and automatic extension is not enabled or not possible
+ * @return the byte that has been written or @c EOF when the end of the
+ * stream is reached, and automatic extension is not enabled or not possible
  * @see cxBufferTerminate()
  */
 cx_attr_nonnull
@@ -630,28 +546,61 @@
 /**
  * Writes a terminating zero to a buffer at the current position.
  *
- * If successful, sets the size to the current position and advances the position by one.
+ * If successful, also sets the size to the current position and shrinks the buffer.
  *
  * The purpose of this function is to have the written data ready to be used as
  * a C string with the buffer's size being the length of that string.
  *
  * @param buffer the buffer to write to
  * @return zero, if the terminator could be written, non-zero otherwise
+ * @see cxBufferShrink()
  */
 cx_attr_nonnull
 CX_EXPORT int cxBufferTerminate(CxBuffer *buffer);
 
 /**
- * Writes a string to a buffer.
- *
- * This is a convenience function for <code>cxBufferWrite(str, 1, strlen(str), buffer)</code>.
+ * Internal function - do not use.
  *
  * @param buffer the buffer
- * @param str the zero-terminated string
+ * @param str the string
  * @return the number of bytes written
+ * @see cxBufferPutString()
+ */
+cx_attr_nonnull
+CX_EXPORT size_t cx_buffer_put_string(CxBuffer *buffer, cxstring str);
+
+/**
+ * Writes a string to a buffer with cxBufferWrite().
+ *
+ * @param buffer (@c CxBuffer*) the buffer
+ * @param str (any string) the zero-terminated string
+ * @return (@c size_t) the number of bytes written
+ * @see cxBufferWrite()
+ * @see cx_strcast()
  */
-cx_attr_nonnull cx_attr_cstr_arg(2)
-CX_EXPORT size_t cxBufferPutString(CxBuffer *buffer, const char *str);
+#define cxBufferPutString(buffer, str) cx_buffer_put_string(buffer, cx_strcast(str))
+
+/**
+ * Internal function - do not use.
+ *
+ * @param buffer the buffer
+ * @param str the string
+ * @return the number of bytes written
+ * @see cxBufferPutString()
+ */
+cx_attr_nonnull
+CX_EXPORT size_t cx_buffer_append_string(CxBuffer *buffer, cxstring str);
+
+/**
+ * Appends a string to a buffer with cxBufferAppend().
+ *
+ * @param buffer (@c CxBuffer*) the buffer
+ * @param str (any string) the zero-terminated string
+ * @return (@c size_t) the number of bytes written
+ * @see cxBufferAppend()
+ * @see cx_strcast()
+ */
+#define cxBufferAppendString(buffer, str) cx_buffer_append_string(buffer, cx_strcast(str))
 
 /**
  * Gets a character from a buffer.
--- a/ucx/cx/collection.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/collection.h	Fri Dec 19 17:53:18 2025 +0100
@@ -58,10 +58,6 @@
      */
     const CxAllocator *allocator;
     /**
-     * The comparator function for the elements.
-     */
-    cx_compare_func cmpfunc;
-    /**
      * The size of each element.
      */
     size_t elem_size;
@@ -70,6 +66,19 @@
      */
     size_t size;
     /**
+     * A two-argument comparator function for the elements.
+     */
+    cx_compare_func simple_cmp;
+    /**
+     * A three-argument comparator function for the elements.
+     * If specified, this function has precedence over the @c simple_cmp function.
+     */
+    cx_compare_func2 advanced_cmp;
+    /**
+     * A pointer to custom data for the @c advanced_cmp function
+     */
+    void *cmp_data;
+    /**
      * An optional simple destructor for the collection's elements.
      *
      * @attention Read the documentation of the particular collection implementation
@@ -139,6 +148,25 @@
  */
 #define cxCollectionStoresPointers(c) ((c)->collection.store_pointer)
 
+
+/**
+ * Convenience macro for adding indirection to an element if the collection is storing pointers.
+ *
+ * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
+ * @param elem the pointer that shall be taken the address from, if the collection is storing pointers
+ * @return if the collection is storing pointers, takes the address of @p elem, otherwise returns @p elem
+ */
+#define cx_ref(c, elem) (cxCollectionStoresPointers(c) ? ((void*)&(elem)) : (elem))
+
+/**
+ * Convenience macro for dereferencing an element if the collection is storing pointers.
+ *
+ * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
+ * @param elem a pointer to the collection element
+ * @return if the collection is storing pointers, dereferences @p elem, otherwise returns @p elem
+ */
+#define cx_deref(c, elem) (cxCollectionStoresPointers(c) ? *((void**)(elem)) : (elem))
+
 /**
  * Indicates whether the collection can guarantee that the stored elements are currently sorted.
  *
@@ -154,29 +182,89 @@
 #define cxCollectionSorted(c) ((c)->collection.sorted || (c)->collection.size == 0)
 
 /**
- * Sets the compare function for a collection.
+ * Sets a simple compare function for a collection.
+ *
+ * Erases a possible advanced compare function.
+ * If you want to set both, because you want to access the simple function
+ * in your advanced function, you must set the simple function first.
+ *
+ * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
+ * @param func (@c cx_compare_func) the compare function
+ */
+#define cxSetCompareFunc(c, func) \
+    (c)->collection.simple_cmp = (cx_compare_func)(func); \
+    (c)->collection.advanced_cmp = NULL
+
+/**
+ * Sets an advanced compare function that supports custom data for a collection.
+ *
+ * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
+ * @param func (@c cx_compare_func2) the compare function
+ * @param data (@c void*) the pointer to custom data that is passed to the compare function
+ */
+#define cxSetAdvancedCompareFunc(c, func, data) \
+    (c)->collection.advanced_cmp = (cx_compare_func2) func; \
+    (c)->collection.cmp_data = data
+
+/**
+ * Invokes the simple comparator function for two elements.
+ *
+ * Usually only used by collection implementations. There should be no need
+ * to invoke this macro manually.
  *
  * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
- * @param func (@c cx_compare_func) the compare function that shall be used by @c c
+ * @param left (@c void*) pointer to data
+ * @param right (@c void*) pointer to data
+ */
+#define cx_invoke_simple_compare_func(c, left, right) \
+    (c)->collection.simple_cmp(left, right)
+
+/**
+ * Invokes the advanced comparator function for two elements.
+ *
+ * Usually only used by collection implementations. There should be no need
+ * to invoke this macro manually.
+ *
+ * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
+ * @param left (@c void*) pointer to data
+ * @param right (@c void*) pointer to data
  */
-#define cxCollectionCompareFunc(c, func) (c)->collection.cmpfunc = (func)
+#define cx_invoke_advanced_compare_func(c, left, right) \
+    (c)->collection.advanced_cmp(left, right, (c)->collection.cmp_data)
+
+
+/**
+ * Invokes the configured comparator function for two elements.
+ *
+ * Usually only used by collection implementations. There should be no need
+ * to invoke this macro manually.
+ *
+ * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
+ * @param left (@c void*) pointer to data
+ * @param right (@c void*) pointer to data
+ */
+#define cx_invoke_compare_func(c, left, right) \
+    (((c)->collection.advanced_cmp) ? \
+    cx_invoke_advanced_compare_func(c,left,right) : \
+    cx_invoke_simple_compare_func(c,left,right))
 
 /**
  * Sets a simple destructor function for this collection.
  *
  * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
- * @param destr the destructor function
+ * @param destr (@c cx_destructor_func) the destructor function
  */
-#define cxDefineDestructor(c, destr) \
+#define cxSetDestructor(c, destr) \
     (c)->collection.simple_destructor = (cx_destructor_func) destr
 
 /**
- * Sets a simple destructor function for this collection.
+ * Sets an advanced destructor function for this collection.
  *
  * @param c a pointer to a struct that contains #CX_COLLECTION_BASE
- * @param destr the destructor function
+ * @param destr (@c cx_destructor_func2) the destructor function
+ * @param data (@c void*) the additional data the advanced destructor is invoked with
  */
-#define cxDefineAdvancedDestructor(c, destr, data) \
+#define cxSetAdvancedDestructor(c, destr, data) \
     (c)->collection.advanced_destructor = (cx_destructor_func2) destr; \
     (c)->collection.destructor_data = data
 
--- a/ucx/cx/common.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/common.h	Fri Dec 19 17:53:18 2025 +0100
@@ -80,10 +80,10 @@
 #define UCX_COMMON_H
 
 /** Major UCX version as integer constant. */
-#define UCX_VERSION_MAJOR   3
+#define UCX_VERSION_MAJOR   4
 
 /** Minor UCX version as integer constant. */
-#define UCX_VERSION_MINOR   1
+#define UCX_VERSION_MINOR   0
 
 /** Version constant which ensures to increase monotonically. */
 #define UCX_VERSION (((UCX_VERSION_MAJOR)<<16)|UCX_VERSION_MINOR)
@@ -284,6 +284,9 @@
  */
 #define CX_INLINE __attribute__((always_inline)) static inline
 #else
+/**
+ * Declares a function to be inlined.
+ */
 #define CX_INLINE static inline
 #endif
 /**
--- a/ucx/cx/compare.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/compare.h	Fri Dec 19 17:53:18 2025 +0100
@@ -57,6 +57,13 @@
 typedef int (*cx_compare_func)(const void *left, const void *right);
 
 /**
+ * A comparator function comparing two arbitrary values.
+ *
+ * Functions with this signature allow specifying a pointer to custom data.
+ */
+typedef int (*cx_compare_func2)(const void *left, const void *right, void *data);
+
+/**
  * Compares two integers of type int.
  *
  * @note the parameters deliberately have type @c void* to be
@@ -527,6 +534,41 @@
 cx_attr_nonnull cx_attr_nodiscard
 CX_EXPORT int cx_cmp_ptr(const void *ptr1, const void *ptr2);
 
+/**
+ * A @c cx_compare_func2 compatible wrapper for @c memcmp().
+ *
+ * @param ptr1 pointer one
+ * @param ptr2 pointer two
+ * @param n (@c size_t*) a pointer to the length
+ * @return the result of @c memcmp()
+ */
+cx_attr_nonnull cx_attr_nodiscard
+CX_EXPORT int cx_ccmp_memcmp(const void *ptr1, const void *ptr2, void *n);
+
+/** Wraps a compare function for cx_ccmp_wrap. */
+typedef struct {
+    /** The wrapped compare function */
+    cx_compare_func cmp;
+} cx_compare_func_wrapper;
+
+/**
+ * A @c cx_compare_func2 wrapper for a @c cx_compare_func().
+ *
+ * This is not strictly compatible with a @c cx_compare_func2 because
+ * ISO C does not define conversions between function and object pointers.
+ *
+ * But it works on all tested platforms to cast a pointer to this function to
+ * a @c cx_compare_func2.
+ *
+ * @param ptr1 pointer one
+ * @param ptr2 pointer two
+ * @param cmp_wrapper a pointer to a @c cx_compare_func_wrapper
+ * @return the result of the invoked compare function
+ * @see cx_compare_func_wrapper_s
+ */
+cx_attr_nonnull cx_attr_nodiscard
+CX_EXPORT int cx_ccmp_wrap(const void *ptr1, const void *ptr2, void* cmp_wrapper);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif
--- a/ucx/cx/hash_map.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/hash_map.h	Fri Dec 19 17:53:18 2025 +0100
@@ -88,22 +88,6 @@
         size_t itemsize, size_t buckets);
 
 /**
- * Creates a new hash map with a default number of buckets.
- *
- * If @p elem_size is #CX_STORE_POINTERS, the created map stores pointers instead of
- * copies of the added elements.
- *
- * @note Iterators provided by this hash map implementation provide the remove operation.
- * The index value of an iterator is incremented when the iterator advanced without
- * removing an entry.
- * In other words, when the iterator is finished, @c index==size .
- *
- * @param itemsize (@c size_t) the size of one element
- * @return (@c CxMap*) a pointer to the new hash map
- */
-#define cxHashMapCreateSimple(itemsize) cxHashMapCreate(NULL, itemsize, 0)
-
-/**
  * Increases the number of buckets, if necessary.
  *
  * The load threshold is @c 0.75*buckets. If the element count exceeds the load
--- a/ucx/cx/iterator.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/iterator.h	Fri Dec 19 17:53:18 2025 +0100
@@ -214,26 +214,15 @@
  * use cxIteratorPtr() to create an iterator which directly
  * yields the stored pointers.
  *
- * While the iterator is in use, the array may only be altered by removing
- * elements through #cxIteratorFlagRemoval(). Every other change to the array
- * will bring this iterator to an undefined state.
- *
- * When @p remove_keeps_order is set to @c false, removing an element will only
- * move the last element to the position of the removed element, instead of
- * moving all subsequent elements by one. Usually, when the order of elements is
- * not important, this parameter should be set to @c false.
- *
  * @param array a pointer to the array (can be @c NULL)
  * @param elem_size the size of one array element
  * @param elem_count the number of elements in the array
- * @param remove_keeps_order @c true if the order of elements must be preserved
- * when removing an element
  * @return an iterator for the specified array
  * @see cxIteratorPtr()
  */
 cx_attr_nodiscard
 CX_EXPORT CxIterator cxIterator(const void *array,
-        size_t elem_size, size_t elem_count, bool remove_keeps_order);
+        size_t elem_size, size_t elem_count);
 
 /**
  * Creates an iterator for the specified plain pointer array.
@@ -243,25 +232,13 @@
  * hand, an iterator created with cxIterator() would return the
  * addresses of those pointers within the array).
  *
- * While the iterator is in use, the array may only be altered by removing
- * elements through #cxIteratorFlagRemoval(). Every other change to the array
- * will bring this iterator to an undefined state.
- *
- * When @p remove_keeps_order is set to @c false, removing an element will only
- * move the last element to the position of the removed element, instead of
- * moving all subsequent elements by one. Usually, when the order of elements is
- * not important, this parameter should be set to @c false.
- *
  * @param array a pointer to the array (can be @c NULL)
  * @param elem_count the number of elements in the array
- * @param remove_keeps_order @c true if the order of elements must be preserved
- * when removing an element
  * @return an iterator for the specified array
  * @see cxIterator()
  */
 cx_attr_nodiscard
-CX_EXPORT CxIterator cxIteratorPtr(const void *array, size_t elem_count,
-        bool remove_keeps_order);
+CX_EXPORT CxIterator cxIteratorPtr(const void *array, size_t elem_count);
 
 #ifdef __cplusplus
 } // extern "C"
--- a/ucx/cx/json.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/json.h	Fri Dec 19 17:53:18 2025 +0100
@@ -41,8 +41,7 @@
 #include "string.h"
 #include "buffer.h"
 #include "array_list.h"
-
-#include <string.h>
+#include "map.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -184,13 +183,10 @@
 typedef struct cx_json_value_s CxJsonValue;
 
 /**
- * Type alias for the JSON array struct.
+ * Type alias for the map representing a JSON object.
+ * The map contains pointers of type @c CxJsonValue.
  */
-typedef struct cx_json_array_s CxJsonArray;
-/**
- * Type alias for the JSON object struct.
- */
-typedef struct cx_json_object_s CxJsonObject;
+typedef CxMap* CxJsonObject;
 /**
  * Type alias for a JSON string.
  */
@@ -209,49 +205,6 @@
 typedef enum cx_json_literal CxJsonLiteral;
 
 /**
- * Type alias for a key/value pair in a JSON object.
- */
-typedef struct cx_json_obj_value_s CxJsonObjValue;
-
-/**
- * JSON array structure.
- */
-struct cx_json_array_s {
-    /**
-     * The array data.
-     */
-    CX_ARRAY_DECLARE(CxJsonValue*, array);
-};
-
-/**
- * JSON object structure.
- */
-struct cx_json_object_s {
-    /**
-     * The key/value entries.
-     */
-    CX_ARRAY_DECLARE(CxJsonObjValue, values);
-    /**
-     * The original indices to reconstruct the order in which the members were added.
-     */
-    size_t *indices;
-};
-
-/**
- * Structure for a key/value entry in a JSON object.
- */
-struct cx_json_obj_value_s {
-    /**
-     * The key (or name in JSON terminology) of the value.
-     */
-    cxmutstr name;
-    /**
-     * The value.
-     */
-    CxJsonValue *value;
-};
-
-/**
  * Structure for a JSON value.
  */
 struct cx_json_value_s {
@@ -274,7 +227,7 @@
         /**
          * The array data if the type is #CX_JSON_ARRAY.
          */
-        CxJsonArray array;
+        CX_ARRAY(CxJsonValue*, array);
         /**
          * The object data if the type is #CX_JSON_OBJECT.
          */
@@ -295,7 +248,7 @@
          * The literal type if the type is #CX_JSON_LITERAL.
          */
         CxJsonLiteral literal;
-    } value;
+    };
 };
 
 /**
@@ -329,6 +282,7 @@
      * The allocator used for produced JSON values.
      */
     const CxAllocator *allocator;
+
     /**
      * The input buffer.
      */
@@ -349,21 +303,21 @@
     CxJsonValue *parsed;
 
     /**
-     * A pointer to an intermediate state of a currently parsed object member.
+     * The name of a not yet completely parsed object member.
      *
      * Never access this value manually.
      */
-    CxJsonObjValue uncompleted_member;
+    cxmutstr uncompleted_member_name;
 
     /**
      * State stack.
      */
-    CX_ARRAY_DECLARE_SIZED(int, states, unsigned);
+    CX_ARRAY(int, states);
 
     /**
      * Value buffer stack.
      */
-    CX_ARRAY_DECLARE_SIZED(CxJsonValue*, vbuf, unsigned);
+    CX_ARRAY(CxJsonValue*, vbuf);
 
     /**
      * Internally reserved memory for the state stack.
@@ -439,10 +393,6 @@
      */
     bool pretty;
     /**
-     * Set false to output the members in the order in which they were added.
-     */
-    bool sort_members;
-    /**
      * The maximum number of fractional digits in a number value.
      * The default value is 6 and values larger than 15 are reduced to 15.
      * Note that the actual number of digits may be lower, depending on the concrete number.
@@ -508,6 +458,33 @@
 CX_EXPORT int cxJsonWrite(void* target, const CxJsonValue* value,
         cx_write_func wfunc, const CxJsonWriter* settings);
 
+
+/**
+ * Produces a compact string representation of the specified JSON value.
+ *
+ * @param allocator the allocator for the string
+ * @param value the JSON value
+ * @return the produced string
+ * @see cxJsonWrite()
+ * @see cxJsonWriterCompact()
+ * @see cxJsonToPrettyString()
+ */
+cx_attr_nonnull_arg(2)
+CX_EXPORT cxmutstr cxJsonToString(const CxAllocator *allocator, CxJsonValue *value);
+
+/**
+ * Produces a pretty string representation of the specified JSON value.
+ *
+ * @param allocator the allocator for the string
+ * @param value the JSON value
+ * @return the produced string
+ * @see cxJsonWrite()
+ * @see cxJsonWriterPretty()
+ * @see cxJsonToString()
+ */
+cx_attr_nonnull_arg(2)
+CX_EXPORT cxmutstr cxJsonToPrettyString(const CxAllocator *allocator, CxJsonValue *value);
+
 /**
  * Initializes the JSON interface.
  *
@@ -530,8 +507,8 @@
 /**
  * Destroys and re-initializes the JSON interface.
  *
- * You might want to use this to reset the parser after
- * encountering a syntax error.
+ * You must use this to reset the parser after encountering a syntax error
+ * if you want to continue using it.
  *
  * @param json the JSON interface
  */
@@ -556,7 +533,7 @@
  * @retval non-zero internal allocation error
  * @see cxJsonFill()
  */
-cx_attr_nonnull cx_attr_access_r(2, 3)
+cx_attr_nonnull_arg(1) cx_attr_access_r(2, 3)
 CX_EXPORT int cxJsonFilln(CxJson *json, const char *buf, size_t len);
 
 
@@ -592,6 +569,36 @@
  */
 #define cxJsonFill(json, str) cx_json_fill(json, cx_strcast(str))
 
+
+/**
+ * Internal function - use cxJsonFromString() instead.
+ *
+ * @param allocator the allocator for the JSON value
+ * @param str the string to parse
+ * @param value a pointer where the JSON value shall be stored to
+ * @return status code
+ */
+cx_attr_nonnull_arg(3)
+CX_EXPORT CxJsonStatus cx_json_from_string(const CxAllocator *allocator,
+            cxstring str, CxJsonValue **value);
+
+/**
+ * Parses a string into a JSON value.
+ *
+ * @param allocator (@c CxAllocator*) the allocator for the JSON value
+ * @param str (any string) the string to parse
+ * @param value (@c CxJsonValue**) a pointer where the JSON value shall be stored to
+ * @retval CX_JSON_NO_ERROR success
+ * @retval CX_JSON_NO_DATA the string was empty or blank
+ * @retval CX_JSON_INCOMPLETE_DATA the string unexpectedly ended
+ * @retval CX_JSON_BUFFER_ALLOC_FAILED allocating internal buffer space failed
+ * @retval CX_JSON_VALUE_ALLOC_FAILED allocating memory for the CxJsonValue failed
+ * @retval CX_JSON_FORMAT_ERROR_NUMBER the JSON text contains an illegally formatted number
+ * @retval CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN JSON syntax error
+ */
+#define cxJsonFromString(allocator, str, value) \
+        cx_json_from_string(allocator, cx_strcast(str), value)
+
 /**
  * Creates a new (empty) JSON object.
  *
@@ -606,13 +613,16 @@
 /**
  * Creates a new (empty) JSON array.
  *
+ * Optionally, this function already allocates memory with the given capacity.
+ *
  * @param allocator the allocator to use
+ * @param capacity optional capacity or zero if it's unknown how many elements the array will have
  * @return the new JSON array or @c NULL if allocation fails
  * @see cxJsonObjPutArr()
  * @see cxJsonArrAddValues()
  */
 cx_attr_nodiscard
-CX_EXPORT CxJsonValue* cxJsonCreateArr(const CxAllocator* allocator);
+CX_EXPORT CxJsonValue* cxJsonCreateArr(const CxAllocator* allocator, size_t capacity);
 
 /**
  * Creates a new JSON number value.
@@ -641,28 +651,27 @@
 /**
  * Creates a new JSON string.
  *
+ * Internal function - use cxJsonCreateString() instead.
+ *
  * @param allocator the allocator to use
  * @param str the string data
  * @return the new JSON value or @c NULL if allocation fails
- * @see cxJsonCreateString()
  * @see cxJsonObjPutString()
- * @see cxJsonArrAddStrings()
+ * @see cxJsonArrAddCxStrings()
  */
-cx_attr_nodiscard cx_attr_nonnull_arg(2) cx_attr_cstr_arg(2)
-CX_EXPORT CxJsonValue* cxJsonCreateString(const CxAllocator* allocator, const char *str);
+cx_attr_nodiscard
+CX_EXPORT CxJsonValue* cx_json_create_string(const CxAllocator* allocator, cxstring str);
 
 /**
  * Creates a new JSON string.
  *
- * @param allocator the allocator to use
- * @param str the string data
- * @return the new JSON value or @c NULL if allocation fails
- * @see cxJsonCreateCxString()
- * @see cxJsonObjPutCxString()
+ * @param allocator (@c CxAllocator*) the allocator to use
+ * @param str the string
+ * @return (@c CxJsonValue*) the new JSON value or @c NULL if allocation fails
+ * @see cxJsonObjPutString()
  * @see cxJsonArrAddCxStrings()
  */
-cx_attr_nodiscard
-CX_EXPORT CxJsonValue* cxJsonCreateCxString(const CxAllocator* allocator, cxstring str);
+#define cxJsonCreateString(allocator, str) cx_json_create_string(allocator, cx_strcast(str))
 
 /**
  * Creates a new JSON literal.
@@ -760,10 +769,7 @@
 /**
  * Adds or replaces a value within a JSON object.
  *
- * The value will be directly added and not copied.
- *
- * @note If a value with the specified @p name already exists,
- * it will be (recursively) freed with its own allocator.
+ * Internal function - use cxJsonObjPut().
  *
  * @param obj the JSON object
  * @param name the name of the value
@@ -772,11 +778,29 @@
  * @retval non-zero allocation failure
  */
 cx_attr_nonnull
-CX_EXPORT int cxJsonObjPut(CxJsonValue* obj, cxstring name, CxJsonValue* child);
+CX_EXPORT int cx_json_obj_put(CxJsonValue* obj, cxstring name, CxJsonValue* child);
+
+/**
+ * Adds or replaces a value within a JSON object.
+ *
+ * The value will be directly added and not copied.
+ *
+ * @note If a value with the specified @p name already exists,
+ * it will be (recursively) freed with its own allocator.
+ *
+ * @param obj (@c CxJsonValue*) the JSON object
+ * @param name (any string) the name of the value
+ * @param child (@c CxJsonValue*) the value
+ * @retval zero success
+ * @retval non-zero allocation failure
+ */
+#define cxJsonObjPut(obj, name, child) cx_json_obj_put(obj, cx_strcast(name), child)
 
 /**
  * Creates a new JSON object and adds it to an existing object.
  *
+ * Internal function - use cxJsonObjPutObj().
+ *
  * @param obj the target JSON object
  * @param name the name of the new value
  * @return the new value or @c NULL if allocation fails
@@ -784,23 +808,51 @@
  * @see cxJsonCreateObj()
  */
 cx_attr_nonnull
-CX_EXPORT CxJsonValue* cxJsonObjPutObj(CxJsonValue* obj, cxstring name);
+CX_EXPORT CxJsonValue* cx_json_obj_put_obj(CxJsonValue* obj, cxstring name);
+
+/**
+ * Creates a new JSON object and adds it to an existing object.
+ *
+ * @param obj (@c CxJsonValue*) the target JSON object
+ * @param name (any string) the name of the new value
+ * @return (@c CxJsonValue*) the new value or @c NULL if allocation fails
+ * @see cxJsonObjPut()
+ * @see cxJsonCreateObj()
+ */
+#define cxJsonObjPutObj(obj, name) cx_json_obj_put_obj(obj, cx_strcast(name))
 
 /**
  * Creates a new JSON array and adds it to an object.
  *
+ * Internal function - use cxJsonObjPutArr().
+ *
  * @param obj the target JSON object
  * @param name the name of the new value
+ * @param capacity optional initial capacity
  * @return the new value or @c NULL if allocation fails
  * @see cxJsonObjPut()
  * @see cxJsonCreateArr()
  */
 cx_attr_nonnull
-CX_EXPORT CxJsonValue* cxJsonObjPutArr(CxJsonValue* obj, cxstring name);
+CX_EXPORT CxJsonValue* cx_json_obj_put_arr(CxJsonValue* obj, cxstring name, size_t capacity);
+
+/**
+ * Creates a new JSON array and adds it to an object.
+ *
+ * @param obj (@c CxJsonValue*) the target JSON object
+ * @param name (any string) the name of the new value
+ * @param capacity (@c size_t) optional initial capacity
+ * @return (@c CxJsonValue*) the new value or @c NULL if allocation fails
+ * @see cxJsonObjPut()
+ * @see cxJsonCreateArr()
+ */
+#define cxJsonObjPutArr(obj, name, capacity) cx_json_obj_put_arr(obj, cx_strcast(name), capacity)
 
 /**
  * Creates a new JSON number and adds it to an object.
  *
+ * Internal function - use cxJsonObjPutNumber().
+ *
  * @param obj the target JSON object
  * @param name the name of the new value
  * @param num the numeric value
@@ -809,11 +861,25 @@
  * @see cxJsonCreateNumber()
  */
 cx_attr_nonnull
-CX_EXPORT CxJsonValue* cxJsonObjPutNumber(CxJsonValue* obj, cxstring name, double num);
+CX_EXPORT CxJsonValue* cx_json_obj_put_number(CxJsonValue* obj, cxstring name, double num);
+
+/**
+ * Creates a new JSON number and adds it to an object.
+ *
+ * @param obj (@c CxJsonValue*) the target JSON object
+ * @param name (any string) the name of the new value
+ * @param num (@c double) the numeric value
+ * @return (@c CxJsonValue*) the new value or @c NULL if allocation fails
+ * @see cxJsonObjPut()
+ * @see cxJsonCreateNumber()
+ */
+#define cxJsonObjPutNumber(obj, name, num) cx_json_obj_put_number(obj, cx_strcast(name), num)
 
 /**
  * Creates a new JSON number, based on an integer, and adds it to an object.
  *
+ * Internal function - use cxJsonObjPutInteger().
+ *
  * @param obj the target JSON object
  * @param name the name of the new value
  * @param num the numeric value
@@ -822,12 +888,24 @@
  * @see cxJsonCreateInteger()
  */
 cx_attr_nonnull
-CX_EXPORT CxJsonValue* cxJsonObjPutInteger(CxJsonValue* obj, cxstring name, int64_t num);
+CX_EXPORT CxJsonValue* cx_json_obj_put_integer(CxJsonValue* obj, cxstring name, int64_t num);
+
+/**
+ * Creates a new JSON number, based on an integer, and adds it to an object.
+ *
+ * @param obj (@c CxJsonValue*) the target JSON object
+ * @param name (any string) the name of the new value
+ * @param num (@c int64_t) the numeric value
+ * @return (@c CxJsonValue*) the new value or @c NULL if allocation fails
+ * @see cxJsonObjPut()
+ * @see cxJsonCreateInteger()
+ */
+#define cxJsonObjPutInteger(obj, name, num) cx_json_obj_put_integer(obj, cx_strcast(name), num)
 
 /**
  * Creates a new JSON string and adds it to an object.
  *
- * The string data is copied.
+ * Internal function - use cxJsonObjPutString()
  *
  * @param obj the target JSON object
  * @param name the name of the new value
@@ -836,27 +914,28 @@
  * @see cxJsonObjPut()
  * @see cxJsonCreateString()
  */
-cx_attr_nonnull cx_attr_cstr_arg(3)
-CX_EXPORT CxJsonValue* cxJsonObjPutString(CxJsonValue* obj, cxstring name, const char* str);
+cx_attr_nonnull
+CX_EXPORT CxJsonValue* cx_json_obj_put_string(CxJsonValue* obj, cxstring name, cxstring str);
 
 /**
  * Creates a new JSON string and adds it to an object.
  *
  * The string data is copied.
  *
- * @param obj the target JSON object
- * @param name the name of the new value
- * @param str the string data
- * @return the new value or @c NULL if allocation fails
+ * @param obj (@c CxJsonValue*) the target JSON object
+ * @param name (any string) the name of the new value
+ * @param str (any string) the string data
+ * @return (@c CxJsonValue*) the new value or @c NULL if allocation fails
  * @see cxJsonObjPut()
- * @see cxJsonCreateCxString()
+ * @see cxJsonCreateString()
  */
-cx_attr_nonnull
-CX_EXPORT CxJsonValue* cxJsonObjPutCxString(CxJsonValue* obj, cxstring name, cxstring str);
+#define cxJsonObjPutString(obj, name, str) cx_json_obj_put_string(obj, cx_strcast(name), cx_strcast(str))
 
 /**
  * Creates a new JSON literal and adds it to an object.
  *
+ * Internal function - use cxJsonObjPutLiteral().
+ *
  * @param obj the target JSON object
  * @param name the name of the new value
  * @param lit the type of literal
@@ -865,7 +944,19 @@
  * @see cxJsonCreateLiteral()
  */
 cx_attr_nonnull
-CX_EXPORT CxJsonValue* cxJsonObjPutLiteral(CxJsonValue* obj, cxstring name, CxJsonLiteral lit);
+CX_EXPORT CxJsonValue* cx_json_obj_put_literal(CxJsonValue* obj, cxstring name, CxJsonLiteral lit);
+
+/**
+ * Creates a new JSON literal and adds it to an object.
+ *
+ * @param obj (@c CxJsonValue*) the target JSON object
+ * @param name (any string) the name of the new value
+ * @param lit (@c CxJsonLiteral) the type of literal
+ * @return (@c CxJsonValue*) the new value or @c NULL if allocation fails
+ * @see cxJsonObjPut()
+ * @see cxJsonCreateLiteral()
+ */
+#define cxJsonObjPutLiteral(obj, name, lit) cx_json_obj_put_literal(obj, cx_strcast(name), lit)
 
 /**
  * Recursively deallocates the memory of a JSON value.
@@ -998,7 +1089,7 @@
  */
 cx_attr_nonnull
 CX_INLINE bool cxJsonIsBool(const CxJsonValue *value) {
-    return cxJsonIsLiteral(value) && value->value.literal != CX_JSON_NULL;
+    return cxJsonIsLiteral(value) && value->literal != CX_JSON_NULL;
 }
 
 /**
@@ -1015,7 +1106,7 @@
  */
 cx_attr_nonnull
 CX_INLINE bool cxJsonIsTrue(const CxJsonValue *value) {
-    return cxJsonIsLiteral(value) && value->value.literal == CX_JSON_TRUE;
+    return cxJsonIsLiteral(value) && value->literal == CX_JSON_TRUE;
 }
 
 /**
@@ -1032,7 +1123,7 @@
  */
 cx_attr_nonnull
 CX_INLINE bool cxJsonIsFalse(const CxJsonValue *value) {
-    return cxJsonIsLiteral(value) && value->value.literal == CX_JSON_FALSE;
+    return cxJsonIsLiteral(value) && value->literal == CX_JSON_FALSE;
 }
 
 /**
@@ -1045,7 +1136,7 @@
  */
 cx_attr_nonnull
 CX_INLINE bool cxJsonIsNull(const CxJsonValue *value) {
-    return cxJsonIsLiteral(value) && value->value.literal == CX_JSON_NULL;
+    return cxJsonIsLiteral(value) && value->literal == CX_JSON_NULL;
 }
 
 /**
@@ -1123,7 +1214,7 @@
  */
 cx_attr_nonnull
 CX_INLINE bool cxJsonAsBool(const CxJsonValue *value) {
-    return value->value.literal == CX_JSON_TRUE;
+    return value->literal == CX_JSON_TRUE;
 }
 
 /**
@@ -1137,7 +1228,7 @@
  */
 cx_attr_nonnull
 CX_INLINE size_t cxJsonArrSize(const CxJsonValue *value) {
-    return value->value.array.array_size;
+    return value->array.size;
 }
 
 /**
@@ -1188,10 +1279,24 @@
 CX_EXPORT CxIterator cxJsonArrIter(const CxJsonValue *value);
 
 /**
- * Returns an iterator over the JSON object members.
+ * Returns the size of a JSON object.
+ *
+ * If the @p value is not a JSON object, the behavior is undefined.
  *
- * The iterator yields values of type @c CxJsonObjValue* which
- * contain the name and value of the member.
+ * @param value the JSON value
+ * @return the size of the object, i.e., the number of key/value pairs
+ * @see cxJsonIsObject()
+ */
+cx_attr_nonnull
+CX_INLINE size_t cxJsonObjSize(const CxJsonValue *value) {
+    return cxCollectionSize(value->object);
+}
+
+/**
+ * Returns a map iterator over the JSON object members.
+ *
+ * The iterator yields values of type @c CxMapEntry* which
+ * contain the name and the @c CxJsonObjValue* of the member.
  *
  * If the @p value is not a JSON object, the behavior is undefined.
  *
@@ -1200,7 +1305,7 @@
  * @see cxJsonIsObject()
  */
 cx_attr_nonnull cx_attr_nodiscard
-CX_EXPORT CxIterator cxJsonObjIter(const CxJsonValue *value);
+CX_EXPORT CxMapIterator cxJsonObjIter(const CxJsonValue *value);
 
 /**
  * Internal function, do not use.
@@ -1251,6 +1356,66 @@
  */
 #define cxJsonObjRemove(value, name) cx_json_obj_remove(value, cx_strcast(name))
 
+/**
+ * Performs a deep comparison of two JSON values.
+ *
+ * The order of object members is ignored during comparison.
+ *
+ * @param json the JSON value
+ * @param other the other JSON value that the JSON value is compared to
+ * @retval zero the values are equal (except for ordering of object members)
+ * @retval non-zero the values differ
+ */
+CX_EXPORT int cxJsonCompare(const CxJsonValue *json, const CxJsonValue *other);
+
+
+/**
+ * Creates a deep copy of the specified JSON value.
+ *
+ * If you need a @c cx_clone_func compatible version, see cxJsonCloneFunc().
+ *
+ * @note when you are cloning @c NULL, you will get a pointer to a statically
+ * allocated value which represents nothing.
+ *
+ * @param value the value to be cloned
+ * @param allocator the allocator for the new value
+ * @return the new value or @c NULL if any allocation was unsuccessful
+ * @see cxJsonCloneFunc()
+ */
+cx_attr_nodiscard
+CX_EXPORT CxJsonValue* cxJsonClone(const CxJsonValue* value,
+        const CxAllocator* allocator);
+
+
+/**
+ * A @c cx_clone_func compatible version of cxJsonClone().
+ *
+ * Internal function - use cxJsonCloneFunc() to get a properly casted function pointer.
+ *
+ * @param target the target memory or @c NULL
+ * @param source the value to be cloned
+ * @param allocator the allocator for the new value
+ * @param data unused
+ * @return the new value or @c NULL if any allocation was unsuccessful
+ * @see cxJsonClone()
+ */
+cx_attr_nodiscard
+CX_EXPORT CxJsonValue* cx_json_clone_func(
+        CxJsonValue* target, const CxJsonValue* source,
+        const CxAllocator* allocator, void *data);
+
+/**
+ * A @c cx_clone_func compatible version of cxJsonClone().
+ *
+ * @param target (@c CxJsonValue*) the target memory or @c NULL
+ * @param source (@c CxJsonValue*) the value to be cloned
+ * @param allocator (@c CxAllocator*) the allocator for the new value
+ * @param data unused
+ * @return the new value or @c NULL if any allocation was unsuccessful
+ * @see cxJsonClone()
+ */
+#define cxJsonCloneFunc  ((cx_clone_func) cx_json_clone_func)
+
 #ifdef __cplusplus
 }
 #endif
--- a/ucx/cx/kv_list.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/kv_list.h	Fri Dec 19 17:53:18 2025 +0100
@@ -49,7 +49,7 @@
  *
  * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
  * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr() if none is given.
+ * to cx_cmp_ptr().
  *
  * After creating the list, it can also be used as a map after converting the pointer
  * to a CxMap pointer with cxKvListAsMap().
@@ -58,9 +58,6 @@
  *
  * @param allocator the allocator for allocating the list nodes
  * (if @c NULL, the cxDefaultAllocator will be used)
- * @param comparator the comparator for the elements
- * (if @c NULL, and the list is not storing pointers, sort and find
- * functions will not work)
  * @param elem_size the size of each element in bytes
  * @return the created list
  * @see cxKvListAsMap()
@@ -68,14 +65,14 @@
  */
 cx_attr_nodiscard cx_attr_malloc cx_attr_dealloc(cxListFree, 1)
 CX_EXPORT CxList *cxKvListCreate(const CxAllocator *allocator,
-        cx_compare_func comparator, size_t elem_size);
+        size_t elem_size);
 
 /**
  * Allocates a linked list with a lookup-map for storing elements with @p elem_size bytes each.
  *
  * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
  * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr() if none is given.
+ * to cx_cmp_ptr().
  *
  * This function creates the list with cxKvListCreate() and immediately applies
  * cxKvListAsMap(). If you want to use the returned object as a list, you can call
@@ -83,9 +80,6 @@
  *
  * @param allocator the allocator for allocating the list nodes
  * (if @c NULL, the cxDefaultAllocator will be used)
- * @param comparator the comparator for the elements
- * (if @c NULL, and the list is not storing pointers, sort and find
- * functions will not work)
  * @param elem_size the size of each element in bytes
  * @return the created list wrapped into the CxMap interface
  * @see cxKvListAsMap()
@@ -93,52 +87,7 @@
  */
 cx_attr_nodiscard cx_attr_malloc cx_attr_dealloc(cxMapFree, 1)
 CX_EXPORT CxMap *cxKvListCreateAsMap(const CxAllocator *allocator,
-        cx_compare_func comparator, size_t elem_size);
-
-/**
- * Allocates a linked list with a lookup-map for storing elements with @p elem_size bytes each.
- *
- * The list will use cxDefaultAllocator and no comparator function. If you want
- * to call functions that need a comparator, you must either set one immediately
- * after list creation or use cxKvListCreate().
- *
- * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
- * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr().
- *
- * After creating the list, it can also be used as a map after converting the pointer
- * to a CxMap pointer with cxKvListAsMap().
- * When you want to use the list interface again, you can also convert the map pointer back
- * with cxKvListAsList().
- *
- * @param elem_size (@c size_t) the size of each element in bytes
- * @return (@c CxList*) the created list
- * @see cxKvListAsMap()
- * @see cxKvListAsList()
- */
-#define cxKvListCreateSimple(elem_size) cxKvListCreate(NULL, NULL, elem_size)
-
-/**
- * Allocates a linked list with a lookup-map for storing elements with @p elem_size bytes each.
- *
- * The list will use cxDefaultAllocator and no comparator function. If you want
- * to call functions that need a comparator, you must either set one immediately
- * after list creation or use cxKvListCreate().
- *
- * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
- * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr().
- *
- * This macro behaves as if the list was created with cxKvListCreateSimple() and
- * immediately followed up by cxKvListAsMap().
- * If you want to use the returned object as a list, you can call cxKvListAsList() later.
- *
- * @param elem_size (@c size_t) the size of each element in bytes
- * @return (@c CxMap*) the created list wrapped into the CxMap interface
- * @see cxKvListAsMap()
- * @see cxKvListAsList()
- */
-#define cxKvListCreateAsMapSimple(elem_size) cxKvListCreateAsMap(NULL, NULL, elem_size)
+        size_t elem_size);
 
 /**
  * Converts a map pointer belonging to a key-value-List back to the original list pointer.
@@ -152,7 +101,7 @@
 /**
  * Converts a map pointer belonging to a key-value-List back to the original list pointer.
  *
- * @param list a list created by cxKvListCreate() or cxKvListCreateSimple()
+ * @param list a list created by cxKvListCreate()
  * @return a map pointer that lets you use the list as if it was a map
  */
 cx_attr_nodiscard cx_attr_nonnull cx_attr_returns_nonnull
--- a/ucx/cx/linked_list.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/linked_list.h	Fri Dec 19 17:53:18 2025 +0100
@@ -62,7 +62,14 @@
      */
     off_t loc_data;
     /**
+     * Location of extra data (optional).
+     * Negative when no extra data is requested.
+     * @see cx_linked_list_extra_data()
+     */
+    off_t loc_extra;
+    /**
      * Additional bytes to allocate @em behind the payload (e.g. for metadata).
+     * @see cx_linked_list_extra_data()
      */
     size_t extra_data_len;
     /**
@@ -80,36 +87,33 @@
  *
  * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
  * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr() if none is given.
+ * to cx_cmp_ptr().
  *
  * @param allocator the allocator for allocating the list nodes
  * (if @c NULL, the cxDefaultAllocator will be used)
- * @param comparator the comparator for the elements
- * (if @c NULL, and the list is not storing pointers, sort and find
- * functions will not work)
  * @param elem_size the size of each element in bytes
  * @return the created list
  */
 cx_attr_nodiscard cx_attr_malloc cx_attr_dealloc(cxListFree, 1)
 CX_EXPORT CxList *cxLinkedListCreate(const CxAllocator *allocator,
-        cx_compare_func comparator, size_t elem_size);
+        size_t elem_size);
 
 /**
- * Allocates a linked list for storing elements with @p elem_size bytes each.
+ * Instructs the linked list to reserve extra data in each node.
  *
- * The list will use cxDefaultAllocator and no comparator function. If you want
- * to call functions that need a comparator, you must either set one immediately
- * after list creation or use cxLinkedListCreate().
+ * The extra data will be aligned and placed behind the element data.
+ * The exact location in the node is stored in the @c loc_extra field
+ * of the linked list.
  *
- * If @p elem_size is #CX_STORE_POINTERS, the created list stores pointers instead of
- * copies of the added elements, and the compare function will be automatically set
- * to cx_cmp_ptr().
+ * You should usually not use this function except when you are creating an
+ * own linked-list implementation that is based on the UCX linked list and
+ * needs to store extra data in each node.
  *
- * @param elem_size (@c size_t) the size of each element in bytes
- * @return (@c CxList*) the created list
+ * @param list the list (must be a linked list)
+ * @param len the length of the extra data
  */
-#define cxLinkedListCreateSimple(elem_size) \
-        cxLinkedListCreate(NULL, NULL, elem_size)
+cx_attr_nonnull
+CX_EXPORT void cx_linked_list_extra_data(cx_linked_list *list, size_t len);
 
 /**
  * Finds the node at a certain index.
@@ -138,16 +142,34 @@
  * @param start a pointer to the start node
  * @param loc_advance the location of the pointer to advance
  * @param loc_data the location of the @c data pointer within your node struct
- * @param cmp_func a compare function to compare @p elem against the node data
  * @param elem a pointer to the element to find
  * @param found_index an optional pointer where the index of the found node
  * (given that @p start has index 0) is stored
+ * @param cmp_func a compare function to compare @p elem against the node data
  * @return a pointer to the found node or @c NULL if no matching node was found
  */
-cx_attr_nonnull_arg(1, 4, 5)
+cx_attr_nonnull_arg(1, 4, 6)
 CX_EXPORT void *cx_linked_list_find(const void *start, ptrdiff_t loc_advance,
-        ptrdiff_t loc_data, cx_compare_func cmp_func, const void *elem,
-        size_t *found_index);
+        ptrdiff_t loc_data, const void *elem, size_t *found_index,
+        cx_compare_func cmp_func);
+
+/**
+ * Finds the node containing an element within a linked list.
+ *
+ * @param start a pointer to the start node
+ * @param loc_advance the location of the pointer to advance
+ * @param loc_data the location of the @c data pointer within your node struct
+ * @param elem a pointer to the element to find
+ * @param found_index an optional pointer where the index of the found node
+ * (given that @p start has index 0) is stored
+ * @param cmp_func a compare function to compare @p elem against the node data
+ * @param context additional context for the compare function
+ * @return a pointer to the found node or @c NULL if no matching node was found
+ */
+cx_attr_nonnull_arg(1, 4, 6)
+CX_EXPORT void *cx_linked_list_find_c(const void *start, ptrdiff_t loc_advance,
+        ptrdiff_t loc_data, const void *elem, size_t *found_index,
+        cx_compare_func2 cmp_func, void *context);
 
 /**
  * Finds the first node in a linked list.
@@ -370,6 +392,92 @@
         ptrdiff_t loc_prev, ptrdiff_t loc_next, void *insert_begin, cx_compare_func cmp_func);
 
 /**
+ * Inserts a node into a sorted linked list.
+ * The new node must not be part of any list yet.
+ *
+ * If the list starting with the node pointed to by @p begin is not sorted
+ * already, the behavior is undefined.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (if your list has one)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param new_node a pointer to the node that shall be inserted
+ * @param cmp_func a compare function that will receive the node pointers
+ * @param context context for the compare function
+ */
+cx_attr_nonnull_arg(1, 5, 6)
+CX_EXPORT void cx_linked_list_insert_sorted_c(void **begin, void **end,
+        ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node, cx_compare_func2 cmp_func, void *context);
+
+/**
+ * Inserts a chain of nodes into a sorted linked list.
+ * The chain must not be part of any list yet.
+ *
+ * If either the list starting with the node pointed to by @p begin or the list
+ * starting with @p insert_begin is not sorted, the behavior is undefined.
+ *
+ * @attention In contrast to cx_linked_list_insert_chain(), the source chain
+ * will be broken and inserted into the target list so that the resulting list
+ * will be sorted according to @p cmp_func. That means each node in the source
+ * chain may be re-linked with nodes from the target list.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (if your list has one)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param insert_begin a pointer to the first node of the chain that shall be inserted
+ * @param cmp_func a compare function that will receive the node pointers
+ * @param context context for the compare function
+ */
+cx_attr_nonnull_arg(1, 5, 6)
+CX_EXPORT void cx_linked_list_insert_sorted_chain_c(void **begin, void **end,
+        ptrdiff_t loc_prev, ptrdiff_t loc_next, void *insert_begin, cx_compare_func2 cmp_func, void *context);
+
+/**
+ * Inserts a node into a sorted linked list if no other node with the same value already exists.
+ * The new node must not be part of any list yet.
+ *
+ * If the list starting with the node pointed to by @p begin is not sorted
+ * already, the behavior is undefined.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (if your list has one)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param new_node a pointer to the node that shall be inserted
+ * @param cmp_func a compare function that will receive the node pointers
+ * @retval zero when the node was inserted
+ * @retval non-zero when a node with the same value already exists
+ */
+cx_attr_nonnull_arg(1, 5, 6)
+CX_EXPORT int cx_linked_list_insert_unique_c(void **begin, void **end,
+        ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node, cx_compare_func2 cmp_func, void *context);
+
+/**
+ * Inserts a chain of nodes into a sorted linked list, avoiding duplicates.
+ * The chain must not be part of any list yet.
+ *
+ * If either the list starting with the node pointed to by @p begin or the list
+ * starting with @p insert_begin is not sorted, the behavior is undefined.
+ *
+ * @attention In contrast to cx_linked_list_insert_sorted(), not all nodes of the
+ * chain might be added. This function returns a new chain consisting of all the duplicates.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (if your list has one)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param insert_begin a pointer to the first node of the chain that shall be inserted
+ * @param cmp_func a compare function that will receive the node pointers
+ * @param context context for the compare function
+ * @return a pointer to a new chain with all duplicates that were not inserted (or @c NULL when there were no duplicates)
+ */
+cx_attr_nonnull_arg(1, 5, 6) cx_attr_nodiscard
+CX_EXPORT void *cx_linked_list_insert_unique_chain_c(void **begin, void **end,
+        ptrdiff_t loc_prev, ptrdiff_t loc_next, void *insert_begin, cx_compare_func2 cmp_func, void *context);
+
+/**
  * Removes a chain of nodes from the linked list.
  *
  * If one of the nodes to remove is the beginning (resp. end) node of the list, and if @p begin (resp. @p end)
@@ -430,16 +538,6 @@
 /**
  * Sorts a linked list based on a comparison function.
  *
- * This function can work with linked lists of the following structure:
- * @code
- * typedef struct node node;
- * struct node {
- *   node* prev;
- *   node* next;
- *   my_payload data;
- * }
- * @endcode
- *
  * @note This is a recursive function with at most logarithmic recursion depth.
  *
  * @param begin a pointer to the beginning node pointer (required)
@@ -453,6 +551,23 @@
 CX_EXPORT void cx_linked_list_sort(void **begin, void **end,
         ptrdiff_t loc_prev, ptrdiff_t loc_next, ptrdiff_t loc_data, cx_compare_func cmp_func);
 
+/**
+ * Sorts a linked list based on a comparison function.
+ *
+ * @note This is a recursive function with at most logarithmic recursion depth.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (optional)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if not present)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param loc_data the location of the @c data pointer within your node struct
+ * @param cmp_func the compare function defining the sort order
+ * @param context additional context for the compare function
+ */
+cx_attr_nonnull_arg(1, 6)
+CX_EXPORT void cx_linked_list_sort_c(void **begin, void **end,
+        ptrdiff_t loc_prev, ptrdiff_t loc_next, ptrdiff_t loc_data, cx_compare_func2 cmp_func, void *context);
+
 
 /**
  * Compares two lists element wise.
@@ -472,6 +587,23 @@
         ptrdiff_t loc_advance, ptrdiff_t loc_data, cx_compare_func cmp_func);
 
 /**
+ * Compares two lists element wise.
+ *
+ * @attention Both lists must have the same structure.
+ *
+ * @param begin_left the beginning of the left list (@c NULL denotes an empty list)
+ * @param begin_right the beginning of the right list  (@c NULL denotes an empty list)
+ * @param loc_advance the location of the pointer to advance
+ * @param loc_data the location of the @c data pointer within your node struct
+ * @param cmp_func the function to compare the elements
+ * @return the first non-zero result of invoking @p cmp_func or: negative if the left list is smaller than the
+ * right list, positive if the left list is larger than the right list, zero if both lists are equal.
+ */
+cx_attr_nonnull_arg(5)
+CX_EXPORT int cx_linked_list_compare_c(const void *begin_left, const void *begin_right,
+        ptrdiff_t loc_advance, ptrdiff_t loc_data, cx_compare_func2 cmp_func, void *context);
+
+/**
  * Reverses the order of the nodes in a linked list.
  *
  * @param begin a pointer to the beginning node pointer (required)
--- a/ucx/cx/list.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/list.h	Fri Dec 19 17:53:18 2025 +0100
@@ -60,10 +60,6 @@
      * The list class definition.
      */
     const cx_list_class *cl;
-    /**
-     * The actual implementation in case the list class is delegating.
-     */
-    const cx_list_class *climpl;
 };
 
 /**
@@ -170,6 +166,12 @@
     void (*reverse)(struct cx_list_s *list);
 
     /**
+     * Optional member function for changing the capacity.
+     * If the list does not support overallocation, this can be set to @c NULL.
+     */
+    int (*change_capacity)(struct cx_list_s *list, size_t new_capacity);
+
+    /**
      * Member function for returning an iterator pointing to the specified index.
      */
     struct cx_iterator_s (*iterator)(const struct cx_list_s *list, size_t index, bool backward);
@@ -285,30 +287,26 @@
  * The purpose of this function is to be called in the initialization code
  * of your list to set certain members correctly.
  *
- * This is particularly important when you want your list to support
- * #CX_STORE_POINTERS as @p elem_size. This function will wrap the list
- * class accordingly and make sure that you can implement your list as if
- * it was only storing objects, and the wrapper will automatically enable
- * the feature of storing pointers.
+ * This is particularly useful when you want your list to support
+ * #CX_STORE_POINTERS as @p elem_size.
  *
  * @par Example
  *
  * @code
  * CxList *myCustomListCreate(
  *         const CxAllocator *allocator,
- *         cx_compare_func comparator,
  *         size_t elem_size
  * ) {
  *     if (allocator == NULL) {
  *         allocator = cxDefaultAllocator;
  *     }
  *
- *     MyCustomList *list = cxCalloc(allocator, 1, sizeof(MyCustomList));
+ *     MyCustomList *list = cxZalloc(allocator, sizeof(MyCustomList));
  *     if (list == NULL) return NULL;
  *
  *     // initialize
  *     cx_list_init((CxList*)list, &my_custom_list_class,
- *             allocator, comparator, elem_size);
+ *             allocator, elem_size);
  *
  *     // ... some more custom stuff ...
  *
@@ -319,13 +317,24 @@
  * @param list the list to initialize
  * @param cl the list class
  * @param allocator the allocator for the elements
- * @param comparator a compare function for the elements
  * @param elem_size the size of one element
  */
 cx_attr_nonnull_arg(1, 2, 3)
 CX_EXPORT void cx_list_init(struct cx_list_s *list,
     struct cx_list_class_s *cl, const struct cx_allocator_s *allocator,
-    cx_compare_func comparator, size_t elem_size);
+    size_t elem_size);
+
+/**
+ * A @c cx_compare_func2 compatible wrapper for the compare functions of a list.
+ *
+ * @param left first element
+ * @param right second element
+ * @param list the list which is comparing the elements
+ * @return the comparison result
+ */
+cx_attr_nonnull
+CX_EXPORT int cx_list_compare_wrapper(
+    const void *left, const void *right, void *list);
 
 /**
  * Returns the number of elements currently stored in the list.
@@ -978,7 +987,7 @@
  * @param data optional additional data that is passed to the clone function
  * @retval zero when all elements were successfully cloned
  * @retval non-zero when an allocation error occurred
- * @see cxListUnion()
+ * @see cxListCloneShallow()
  */
 cx_attr_nonnull_arg(1, 2, 3)
 CX_EXPORT int cxListClone(CxList *dst, const CxList *src,
@@ -1001,6 +1010,7 @@
  * @param data optional additional data that is passed to the clone function
  * @retval zero when the elements were successfully cloned
  * @retval non-zero when an allocation error occurred
+ * @see cxListDifferenceShallow()
  */
 cx_attr_nonnull_arg(1, 2, 3, 4)
 CX_EXPORT int cxListDifference(CxList *dst,
@@ -1024,6 +1034,7 @@
  * @param data optional additional data that is passed to the clone function
  * @retval zero when the elements were successfully cloned
  * @retval non-zero when an allocation error occurred
+ * @see cxListIntersectionShallow()
  */
 cx_attr_nonnull_arg(1, 2, 3, 4)
 CX_EXPORT int cxListIntersection(CxList *dst, const CxList *src, const CxList *other,
@@ -1048,12 +1059,136 @@
  * @param data optional additional data that is passed to the clone function
  * @retval zero when the elements were successfully cloned
  * @retval non-zero when an allocation error occurred
- * @see cxListClone()
+ * @see cxListUnionShallow()
  */
 cx_attr_nonnull_arg(1, 2, 3, 4)
 CX_EXPORT int cxListUnion(CxList *dst, const CxList *src, const CxList *other,
         cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data);
 
+/**
+ * Performs a shallow clone of one list into another.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * If the destination list already contains elements, the cloned elements
+ * are appended to that list.
+ *
+ * @attention If the cloned elements need to be destroyed by a destructor
+ * function, you must make sure that the destination list also uses this
+ * destructor function.
+ *
+ * @param dst the destination list
+ * @param src the source list
+ * @retval zero when all elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ * @see cxListClone()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxListCloneShallow(CxList *dst, const CxList *src);
+
+/**
+ * Clones elements from a list only if they are not present in another list.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * If the @p minuend does not contain duplicates, this is equivalent to adding
+ * the set difference to the destination list.
+ *
+ * This function is optimized for the case when both the @p minuend and the
+ * @p subtrahend are sorted.
+ *
+ * @param dst the destination list
+ * @param minuend the list to subtract elements from
+ * @param subtrahend the elements that shall be subtracted
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ * @see cxListDifference()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxListDifferenceShallow(CxList *dst,
+        const CxList *minuend, const CxList *subtrahend);
+
+/**
+ * Clones elements from a list only if they are also present in another list.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * This function is optimized for the case when both the @p src and the
+ * @p other list are sorted.
+ *
+ * If the destination list already contains elements, the intersection is appended
+ * to that list.
+ *
+ * @param dst the destination list
+ * @param src the list to clone the elements from
+ * @param other the list to check the elements for existence
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ * @see cxListIntersection()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxListIntersectionShallow(CxList *dst, const CxList *src, const CxList *other);
+
+/**
+ * Performs a deep clone of one list into another, skipping duplicates.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * This function is optimized for the case when both the @p src and the
+ * @p other list are sorted.
+ * In that case, the union will also be sorted.
+ *
+ * If the destination list already contains elements, the union is appended
+ * to that list. In that case the destination is not necessarily sorted.
+ *
+ * @param dst the destination list
+ * @param src the primary source list
+ * @param other the other list, where elements are only cloned from
+ * when they are not in @p src
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ * @see cxListUnion()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxListUnionShallow(CxList *dst, const CxList *src, const CxList *other);
+
+/**
+ * Asks the list to reserve enough memory for a given total number of elements.
+ *
+ * List implementations are free to choose if reserving memory upfront makes
+ * sense.
+ * For example, array-based implementations usually do support reserving memory
+ * for additional elements while linked lists usually don't.
+ *
+ * @note When the requested capacity is smaller than the current size,
+ * this function returns zero without performing any action.
+ *
+ * @param list the list
+ * @param capacity the expected total number of elements
+ * @retval zero on success or when overallocation is not supported
+ * @retval non-zero when an allocation error occurred
+ * @see cxListShrink()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxListReserve(CxList *list, size_t capacity);
+
+/**
+ * Advises the list to free any overallocated memory.
+ *
+ * Lists that do not support overallocation simply return zero.
+ *
+ * This function usually returns zero, except for very special and custom
+ * list and/or allocator implementations where freeing memory can fail.
+ *
+ * @param list the list
+ * @return usually zero
+ */
+cx_attr_nonnull
+CX_EXPORT int cxListShrink(CxList *list);
 
 #ifdef __cplusplus
 } // extern "C"
--- a/ucx/cx/map.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/map.h	Fri Dec 19 17:53:18 2025 +0100
@@ -183,9 +183,9 @@
      * Add or overwrite an element.
      * If the @p value is @c NULL, the implementation
      * shall only allocate memory instead of adding an existing value to the map.
-     * Returns a pointer to the allocated memory or @c NULL if allocation fails.
+     * Returns a map entry where the pointer to the key is @c NULL if allocation fails.
      */
-    void *(*put)(CxMap *map, CxHashKey key, void *value);
+    CxMapEntry (*put)(CxMap *map, CxHashKey key, void *value);
 
     /**
      * Returns an element.
@@ -357,8 +357,6 @@
  * @param map the map
  * @param key the key
  * @return the pointer to the allocated memory or @c NULL if allocation fails
- * @retval zero success
- * @retval non-zero value on memory allocation failure
  * @see cxMapEmplace()
  */
 cx_attr_nonnull
@@ -379,8 +377,6 @@
  * @param map (@c CxMap*) the map
  * @param key (any supported key type) the key
  * @return the pointer to the allocated memory or @c NULL if allocation fails
- * @retval zero success
- * @retval non-zero value on memory allocation failure
  * @see CX_HASH_KEY()
  */
 #define cxMapEmplace(map, key) cx_map_emplace(map, CX_HASH_KEY(key))
@@ -603,6 +599,139 @@
 CX_EXPORT int cxMapUnion(CxMap *dst, const CxMap *src,
         cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data);
 
+/**
+ * Performs a shallow clone of one map into another.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * If the destination map already contains entries, the cloned entries
+ * are added to that map, possibly overwriting existing elements when
+ * the keys already exist.
+ *
+ * When elements in the destination map need to be replaced, any destructor
+ * function is called on the replaced elements before replacing them.
+ *
+ * @attention If the cloned elements need to be destroyed by a destructor
+ * function, you must make sure that the destination map also uses this
+ * destructor function.
+ *
+ * @param dst the destination map
+ * @param src the source map
+ * @retval zero when all elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ * @see cxMapClone()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapCloneShallow(CxMap *dst, const CxMap *src);
+
+/**
+ * Clones entries of a map if their key is not present in another map.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * @param dst the destination map
+ * @param minuend the map to subtract the entries from
+ * @param subtrahend the map containing the elements to be subtracted
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapDifferenceShallow(CxMap *dst, const CxMap *minuend, const CxMap *subtrahend);
+
+/**
+ * Clones entries of a map if their key is not present in a list.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * Note that the list must contain keys of type @c CxKey
+ * (or pointers to such keys) and must use @c cx_hash_key_cmp
+ * as the compare function.
+ * Generic key types cannot be processed in this case.
+ *
+ * @param dst the destination map
+ * @param src the source map
+ * @param keys the list of @c CxKey items
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ * @see cxMapListDifference()
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapListDifferenceShallow(CxMap *dst, const CxMap *src, const CxList *keys);
+
+
+/**
+ * Clones entries of a map only if their key is present in another map.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * @param dst the destination map
+ * @param src the map to clone the entries from
+ * @param other the map to check for existence of the keys
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapIntersectionShallow(CxMap *dst, const CxMap *src, const CxMap *other);
+
+/**
+ * Clones entries of a map only if their key is present in a list.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * Note that the list must contain keys of type @c CxKey
+ * (or pointers to such keys) and must use @c cx_hash_key_cmp
+ * as the compare function.
+ * Generic key types cannot be processed in this case.
+ *
+ * @param dst the destination map
+ * @param src the source map
+ * @param keys the list of @c CxKey items
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapListIntersectionShallow(CxMap *dst, const CxMap *src, const CxList *keys);
+
+/**
+ * Clones entries into a map if their key does not exist yet.
+ *
+ * This function uses the default allocator, if needed, and performs
+ * shallow clones with @c memcpy().
+ *
+ * If you want to calculate the union of two maps into a fresh new map,
+ * you can proceed as follows:
+ * 1. Clone the first map into a fresh, empty map.
+ * 2. Use this function to clone the second map into the result from step 1.
+ *
+ * @param dst the destination map
+ * @param src the map to clone the entries from
+ * @retval zero when the elements were successfully cloned
+ * @retval non-zero when an allocation error occurred
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapUnionShallow(CxMap *dst, const CxMap *src);
+
+
+/**
+ * Compares the entries of two maps.
+ *
+ * @param map the map
+ * @param other the other map that the first map is compared to
+ * @retval zero when both maps have the same key sets
+ * and the values are pairwise equivalent
+ * @retval negative when the first @p map has fewer keys than the @p other map
+ * @retval positive when the first @p map has more keys than the @p other map
+ * @retval non-zero (unspecified whether positive or negative) when the size
+ * of both maps is equal but a key or a value is different
+ */
+cx_attr_nonnull
+CX_EXPORT int cxMapCompare(const CxMap *map, const CxMap *other);
+
 #ifdef    __cplusplus
 } // extern "C"
 #endif
--- a/ucx/cx/properties.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/properties.h	Fri Dec 19 17:53:18 2025 +0100
@@ -41,9 +41,6 @@
 #include "map.h"
 #include "buffer.h"
 
-#include <stdio.h>
-#include <string.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -76,13 +73,10 @@
      */
     char comment3;
 
-    /*
+    /**
      * The character, when appearing at the end of a line, continues that line.
      * This is '\' by default.
      */
-    /**
-     * Reserved for future use.
-     */
     char continuation;
 };
 
@@ -141,23 +135,16 @@
      */
     CX_PROPERTIES_BUFFER_ALLOC_FAILED,
     /**
-     * Initializing the properties source failed.
-     *
-     * @see cx_properties_read_init_func
+     * A file operation failed.
+     * Only for cxPropertiesLoad().
+     * It is system-specific if errno is set.
      */
-    CX_PROPERTIES_READ_INIT_FAILED,
+    CX_PROPERTIES_FILE_ERROR,
     /**
-     * Reading from a properties source failed.
-     *
-     * @see cx_properties_read_func
+     * A map operation failed.
+     * Only for cxPropertiesLoad().
      */
-    CX_PROPERTIES_READ_FAILED,
-    /**
-     * Sinking a k/v-pair failed.
-     *
-     * @see cx_properties_sink_func
-     */
-    CX_PROPERTIES_SINK_FAILED,
+    CX_PROPERTIES_MAP_ERROR,
 };
 
 /**
@@ -190,134 +177,6 @@
  */
 typedef struct cx_properties_s CxProperties;
 
-
-/**
- * Typedef for a properties sink.
- */
-typedef struct cx_properties_sink_s CxPropertiesSink;
-
-/**
- * A function that consumes a k/v-pair in a sink.
- *
- * The sink could be a map, and the sink function would be calling
- * a map function to store the k/v-pair.
- *
- * @param prop the properties interface that wants to sink a k/v-pair
- * @param sink the sink
- * @param key the key
- * @param value the value
- * @retval zero success
- * @retval non-zero sinking the k/v-pair failed
- */
-typedef int(*cx_properties_sink_func)(
-        CxProperties *prop,
-        CxPropertiesSink *sink,
-        cxstring key,
-        cxstring value
-);
-
-/**
- * Defines a sink for k/v-pairs.
- */
-struct cx_properties_sink_s {
-    /**
-     * The sink object.
-     */
-    void *sink;
-    /**
-     * Optional custom data.
-     */
-    void *data;
-    /**
-     * A function for consuming k/v-pairs into the sink.
-     */
-    cx_properties_sink_func sink_func;
-};
-
-
-/**
- * Typedef for a properties source.
- */
-typedef struct cx_properties_source_s CxPropertiesSource;
-
-/**
- * A function that reads data from a source.
- *
- * When the source is depleted, implementations SHALL provide an empty
- * string in the @p target and return zero.
- * A non-zero return value is only permitted in case of an error.
- *
- * The meaning of the optional parameters is implementation-dependent.
- *
- * @param prop the properties interface that wants to read from the source
- * @param src the source
- * @param target a string buffer where the read data shall be stored
- * @retval zero success
- * @retval non-zero reading the data failed
- */
-typedef int(*cx_properties_read_func)(
-        CxProperties *prop,
-        CxPropertiesSource *src,
-        cxstring *target
-);
-
-/**
- * A function that may initialize additional memory for the source.
- *
- * @param prop the properties interface that wants to read from the source
- * @param src the source
- * @retval zero initialization was successful
- * @retval non-zero otherwise
- */
-typedef int(*cx_properties_read_init_func)(
-        CxProperties *prop,
-        CxPropertiesSource *src
-);
-
-/**
- * A function that cleans memory initialized by the read_init_func.
- *
- * @param prop the properties interface that wants to read from the source
- * @param src the source
- */
-typedef void(*cx_properties_read_clean_func)(
-        CxProperties *prop,
-        CxPropertiesSource *src
-);
-
-/**
- * Defines a properties source.
- */
-struct cx_properties_source_s {
-    /**
-     * The source object.
-     *
-     * For example, a file stream or a string.
-     */
-    void *src;
-    /**
-     * Optional additional data pointer.
-     */
-    void *data_ptr;
-    /**
-     * Optional size information.
-     */
-    size_t data_size;
-    /**
-     * A function that reads data from the source.
-     */
-    cx_properties_read_func read_func;
-    /**
-     * Optional function that may prepare the source for reading data.
-     */
-    cx_properties_read_init_func read_init_func;
-    /**
-     * Optional function that cleans additional memory allocated by the
-     * read_init_func.
-     */
-    cx_properties_read_clean_func read_clean_func;
-};
-
 /**
  * Initialize a properties interface.
  *
@@ -465,100 +324,83 @@
 CX_EXPORT CxPropertiesStatus cxPropertiesNext(CxProperties *prop, cxstring *key, cxstring *value);
 
 /**
- * Creates a properties sink for an UCX map.
- *
- * The values stored in the map will be pointers to freshly allocated,
- * zero-terminated C strings (@c char*), which means the @p map should have been
- * created with #CX_STORE_POINTERS.
- *
- * The cxDefaultAllocator will be used unless you specify a custom
- * allocator in the optional @c data field of the returned sink.
- *
- * @param map the map that shall consume the k/v-pairs.
- * @return the sink
- * @see cxPropertiesLoad()
+ * The size of the stack memory that `cxPropertiesLoad()` will reserve with `cxPropertiesUseStack()`.
  */
-cx_attr_nonnull cx_attr_nodiscard
-CX_EXPORT CxPropertiesSink cxPropertiesMapSink(CxMap *map);
+CX_EXPORT extern const unsigned cx_properties_load_buf_size;
 
 /**
- * Creates a properties source based on an UCX string.
- *
- * @param str the string
- * @return the properties source
- * @see cxPropertiesLoad()
+ * The size of the stack memory that `cxPropertiesLoad()` will use to read contents from the file.
  */
-cx_attr_nodiscard
-CX_EXPORT CxPropertiesSource cxPropertiesStringSource(cxstring str);
-
-/**
- * Creates a properties source based on C string with the specified length.
- *
- * @param str the string
- * @param len the length
- * @return the properties source
- * @see cxPropertiesLoad()
- */
-cx_attr_nonnull cx_attr_nodiscard cx_attr_access_r(1, 2)
-CX_EXPORT CxPropertiesSource cxPropertiesCstrnSource(const char *str, size_t len);
+CX_EXPORT extern const unsigned cx_properties_load_fill_size;
 
 /**
- * Creates a properties source based on a C string.
- *
- * The length will be determined with strlen(), so the string MUST be
- * zero-terminated.
+ * Internal function - use cxPropertiesLoad() instead.
  *
- * @param str the string
- * @return the properties source
- * @see cxPropertiesLoad()
+ * @param allocator the allocator for the values
+ * @param filename the file name
+ * @param target the target map
+ * @param config the parser config
+ * @return status code
  */
-cx_attr_nonnull cx_attr_nodiscard cx_attr_cstr_arg(1)
-CX_EXPORT CxPropertiesSource cxPropertiesCstrSource(const char *str);
+cx_attr_nonnull_arg(3)
+CX_EXPORT CxPropertiesStatus cx_properties_load(const CxAllocator *allocator,
+        cxstring filename, CxMap *target, CxPropertiesConfig config);
 
 /**
- * Creates a properties source based on an FILE.
- *
- * @param file the file
- * @param chunk_size how many bytes may be read in one operation
+ * Loads properties from a file and inserts them into a map.
  *
- * @return the properties source
- * @see cxPropertiesLoad()
- */
-cx_attr_nonnull cx_attr_nodiscard cx_attr_access_r(1)
-CX_EXPORT CxPropertiesSource cxPropertiesFileSource(FILE *file, size_t chunk_size);
-
-
-/**
- * Loads properties data from a source and transfers it to a sink.
+ * Entries are added to the map, possibly overwriting existing entries.
+ *
+ * The map must either store pointers of type @c char*, or elements of type cxmutstr.
+ * Any other configuration is not supported.
  *
- * This function tries to read as much data from the source as possible.
- * When the source was completely consumed and at least on k/v-pair was found,
- * the return value will be #CX_PROPERTIES_NO_ERROR.
- * When the source was consumed but no k/v-pairs were found, the return value
- * will be #CX_PROPERTIES_NO_DATA.
- * In case the source data ends unexpectedly, the #CX_PROPERTIES_INCOMPLETE_DATA
- * is returned. In that case you should call this function again with the same
- * sink and either an updated source or the same source if the source is able to
- * yield the missing data.
+ * @note When the parser finds an error, all successfully parsed keys before the error
+ * are added to the map nonetheless.
  *
- * The other result codes apply, according to their description.
- *
- * @param prop the properties interface
- * @param sink the sink
- * @param source the source
- * @retval CX_PROPERTIES_NO_ERROR (zero) a key/value pair was found
- * @retval CX_PROPERTIES_READ_INIT_FAILED initializing the source failed
- * @retval CX_PROPERTIES_READ_FAILED reading from the source failed
- * @retval CX_PROPERTIES_SINK_FAILED sinking the properties into the sink failed
- * @retval CX_PROPERTIES_NO_DATA the source did not provide any key/value pairs
- * @retval CX_PROPERTIES_INCOMPLETE_DATA the source did not provide enough data
+ * @param allocator the allocator for the values that will be stored in the map
+ * @param filename (any string) the absolute or relative path to the file
+ * @param target (@c CxMap*) the map where the properties shall be added
+ * @param config the parser config
+ * @retval CX_PROPERTIES_NO_ERROR (zero) at least one key/value pair was found
+ * @retval CX_PROPERTIES_NO_DATA the file is syntactically OK, but does not contain properties
+ * @retval CX_PROPERTIES_INCOMPLETE_DATA unexpected end of file
  * @retval CX_PROPERTIES_INVALID_EMPTY_KEY the properties data contains an illegal empty key
  * @retval CX_PROPERTIES_INVALID_MISSING_DELIMITER the properties data contains a line without delimiter
  * @retval CX_PROPERTIES_BUFFER_ALLOC_FAILED an internal allocation was necessary but failed
+ * @retval CX_PROPERTIES_FILE_ERROR a file operation failed; depending on the system @c errno might be set
+ * @retval CX_PROPERTIES_MAP_ERROR storing a key/value pair in the map failed
+ * @see cxPropertiesLoadDefault()
  */
-cx_attr_nonnull
-CX_EXPORT CxPropertiesStatus cxPropertiesLoad(CxProperties *prop,
-        CxPropertiesSink sink, CxPropertiesSource source);
+#define cxPropertiesLoad(allocator, filename, target, config) \
+    cx_properties_load(allocator, cx_strcast(filename), target, config)
+
+/**
+ * Loads properties from a file and inserts them into a map with a default config.
+ *
+ * Entries are added to the map, possibly overwriting existing entries.
+ *
+ * The map must either store pointers of type @c char*, or elements of type cxmutstr.
+ * Any other configuration is not supported.
+ *
+ * @note When the parser finds an error, all successfully parsed keys before the error
+ * are added to the map nonetheless.
+ *
+ * @param allocator the allocator for the values that will be stored in the map
+ * @param filename (any string) the absolute or relative path to the file
+ * @param target (@c CxMap*) the map where the properties shall be added
+ * @retval CX_PROPERTIES_NO_ERROR (zero) at least one key/value pair was found
+ * @retval CX_PROPERTIES_NO_DATA the file is syntactically OK, but does not contain properties
+ * @retval CX_PROPERTIES_INCOMPLETE_DATA unexpected end of file
+ * @retval CX_PROPERTIES_INVALID_EMPTY_KEY the properties data contains an illegal empty key
+ * @retval CX_PROPERTIES_INVALID_MISSING_DELIMITER the properties data contains a line without delimiter
+ * @retval CX_PROPERTIES_BUFFER_ALLOC_FAILED an internal allocation was necessary but failed
+ * @retval CX_PROPERTIES_FILE_ERROR a file operation failed; depending on the system @c errno might be set
+ * @retval CX_PROPERTIES_MAP_ERROR storing a key/value pair in the map failed
+ * @see cxPropertiesLoad()
+ */
+#define cxPropertiesLoadDefault(allocator, filename, target) \
+    cx_properties_load(allocator, cx_strcast(filename), target, cx_properties_config_default)
+
 
 #ifdef __cplusplus
 } // extern "C"
--- a/ucx/cx/string.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/string.h	Fri Dec 19 17:53:18 2025 +0100
@@ -39,6 +39,8 @@
 #include "common.h"
 #include "allocator.h"
 
+#include <string.h>
+
 /** Expands a UCX string as printf arguments. */
 #define CX_SFMT(s) (int) (s).length, (s).ptr
 
@@ -137,30 +139,6 @@
  */
 typedef struct cx_strtok_ctx_s CxStrtokCtx;
 
-#ifdef __cplusplus
-extern "C" {
-
-/**
- * A literal initializer for an UCX string structure.
- *
- * @param literal the string literal
- */
-#define CX_STR(literal) cxstring{literal, sizeof(literal) - 1}
-
-#else // __cplusplus
-
-/**
- * A literal initializer for an UCX string structure.
- *
- * The argument MUST be a string (const char*) @em literal.
- *
- * @param literal the string literal
- */
-#define CX_STR(literal) ((cxstring){literal, sizeof(literal) - 1})
-
-#endif
-
-
 /**
  * Wraps a mutable string that must be zero-terminated.
  *
@@ -179,7 +157,12 @@
  * @see cx_mutstrn()
  */
 cx_attr_nodiscard cx_attr_cstr_arg(1)
-CX_EXPORT cxmutstr cx_mutstr(char *cstring);
+CX_INLINE cxmutstr cx_mutstr(char *cstring) {
+    cxmutstr str;
+    str.ptr = cstring;
+    str.length = cstring == NULL ? 0 : strlen(cstring);
+    return str;
+}
 
 /**
  * Wraps a string that does not need to be zero-terminated.
@@ -198,7 +181,12 @@
  * @see cx_mutstr()
  */
 cx_attr_nodiscard cx_attr_access_rw(1, 2)
-CX_EXPORT cxmutstr cx_mutstrn(char *cstring, size_t length);
+CX_INLINE cxmutstr cx_mutstrn(char *cstring, size_t length) {
+    cxmutstr str;
+    str.ptr = cstring;
+    str.length = length;
+    return str;
+}
 
 /**
  * Wraps a string that must be zero-terminated.
@@ -218,7 +206,12 @@
  * @see cx_strn()
  */
 cx_attr_nodiscard cx_attr_cstr_arg(1)
-CX_EXPORT cxstring cx_str(const char *cstring);
+CX_INLINE cxstring cx_str(const char *cstring) {
+    cxstring str;
+    str.ptr = cstring;
+    str.length = cstring == NULL ? 0 : strlen(cstring);
+    return str;
+}
 
 
 /**
@@ -238,10 +231,14 @@
  * @see cx_str()
  */
 cx_attr_nodiscard cx_attr_access_r(1, 2)
-CX_EXPORT cxstring cx_strn(const char *cstring, size_t length);
+CX_INLINE cxstring cx_strn(const char *cstring, size_t length) {
+    cxstring str;
+    str.ptr = cstring;
+    str.length = length;
+    return str;
+}
 
 #ifdef __cplusplus
-} // extern "C"
 cx_attr_nodiscard
 CX_CPPDECL cxstring cx_strcast(cxmutstr str) {
     return cx_strn(str.ptr, str.length);
@@ -256,7 +253,7 @@
 }
 cx_attr_nodiscard
 CX_CPPDECL cxstring cx_strcast(const unsigned char *str) {
-    return cx_str(static_cast<const char*>(str));
+    return cx_str(reinterpret_cast<const char*>(str));
 }
 extern "C" {
 #else
--- a/ucx/cx/tree.h	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/cx/tree.h	Fri Dec 19 17:53:18 2025 +0100
@@ -88,6 +88,7 @@
     ptrdiff_t loc_next;
     /**
      * The total number of distinct nodes that have been passed so far.
+     * This includes the current node.
      */
     size_t counter;
     /**
@@ -185,6 +186,7 @@
     ptrdiff_t loc_next;
     /**
      * The total number of distinct nodes that have been passed so far.
+     * This includes the currently visited node.
      */
     size_t counter;
     /**
@@ -641,17 +643,13 @@
  * Structure for holding the base data of a tree.
  */
 struct cx_tree_s {
+    CX_COLLECTION_BASE;
     /**
      * The tree class definition.
      */
     const cx_tree_class *cl;
 
     /**
-     * Allocator to allocate new nodes.
-     */
-    const CxAllocator *allocator;
-
-    /**
      * A pointer to the root node.
      *
      * Will be @c NULL when @c size is 0.
@@ -669,21 +667,6 @@
     cx_tree_node_create_func node_create;
 
     /**
-     * An optional simple destructor for the tree nodes.
-     */
-    cx_destructor_func simple_destructor;
-
-    /**
-     * An optional advanced destructor for the tree nodes.
-     */
-    cx_destructor_func2 advanced_destructor;
-
-    /**
-     * The pointer to additional data that is passed to the advanced destructor.
-     */
-    void *destructor_data;
-
-    /**
      * A function to compare two nodes.
      */
     cx_tree_search_func search;
@@ -694,11 +677,6 @@
     cx_tree_search_data_func search_data;
 
     /**
-     * The number of currently stored elements.
-     */
-    size_t size;
-
-    /**
      * Offset in the node struct for the parent pointer.
      */
     ptrdiff_t loc_parent;
@@ -1094,7 +1072,7 @@
  * @see cxTreeIterate()
  */
 cx_attr_nonnull cx_attr_nodiscard
-CxTreeVisitor cxTreeVisit(CxTree *tree);
+CX_EXPORT CxTreeVisitor cxTreeVisit(CxTree *tree);
 
 /**
  * Sets the (new) parent of the specified child.
--- a/ucx/hash_map.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/hash_map.c	Fri Dec 19 17:53:18 2025 +0100
@@ -78,7 +78,7 @@
     cxFree(map->collection.allocator, map);
 }
 
-static void *cx_hash_map_put(
+static CxMapEntry cx_hash_map_put(
         CxMap *map,
         CxHashKey key,
         void *value
@@ -117,7 +117,7 @@
                 allocator,
                 sizeof(struct cx_hash_map_element_s) + map->collection.elem_size
         );
-        if (e == NULL) return NULL;
+        if (e == NULL) return (CxMapEntry){NULL, NULL}; // LCOV_EXCL_LINE
 
         // write the value
         if (value == NULL) {
@@ -130,10 +130,10 @@
 
         // copy the key
         void *kd = cxMalloc(allocator, key.len);
-        if (kd == NULL) {
+        if (kd == NULL) { // LCOV_EXCL_START
             cxFree(allocator, e);
-            return NULL;
-        }
+            return (CxMapEntry){NULL, NULL};
+        } // LCOV_EXCL_STOP
         memcpy(kd, key.data, key.len);
         e->key.data = kd;
         e->key.len = key.len;
@@ -152,8 +152,8 @@
         map->collection.size++;
     }
 
-    // return pointer to the element
-    return elm->data;
+    // return the entry
+    return (CxMapEntry){&elm->key, elm->data};
 }
 
 static void cx_hash_map_unlink(
@@ -414,8 +414,7 @@
         buckets = 16;
     }
 
-    struct cx_hash_map_s *map = cxCalloc(allocator, 1,
-                                         sizeof(struct cx_hash_map_s));
+    struct cx_hash_map_s *map = cxZalloc(allocator, sizeof(struct cx_hash_map_s));
     if (map == NULL) return NULL;
 
     // initialize hash map members
@@ -433,9 +432,12 @@
 
     if (itemsize > 0) {
         map->base.collection.elem_size = itemsize;
+        map->base.collection.advanced_cmp = cx_ccmp_memcmp;
+        map->base.collection.cmp_data = &map->base.collection.elem_size;
     } else {
         map->base.collection.elem_size = sizeof(void *);
         map->base.collection.store_pointer = true;
+        map->base.collection.simple_cmp = cx_cmp_ptr;
     }
 
     return (CxMap *) map;
@@ -447,15 +449,16 @@
 
         size_t new_bucket_count = (map->collection.size * 5) >> 1;
         if (new_bucket_count < hash_map->bucket_count) {
+            // LCOV_EXCL_START
             errno = EOVERFLOW;
             return 1;
-        }
+        } // LCOV_EXCL_STOP
         struct cx_hash_map_element_s **new_buckets = cxCalloc(
                 map->collection.allocator,
                 new_bucket_count, sizeof(struct cx_hash_map_element_s *)
         );
 
-        if (new_buckets == NULL) return 1;
+        if (new_buckets == NULL) return 1; // LCOV_EXCL_LINE
 
         // iterate through the elements and assign them to their new slots
         for (size_t slot = 0; slot < hash_map->bucket_count; slot++) {
--- a/ucx/iterator.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/iterator.c	Fri Dec 19 17:53:18 2025 +0100
@@ -29,6 +29,7 @@
 #include "cx/iterator.h"
 
 #include <string.h>
+#include <assert.h>
 
 static bool cx_iter_valid(const void *it) {
     const struct cx_iterator_s *iter = it;
@@ -45,51 +46,14 @@
     return *(void**)iter->elem_handle;
 }
 
-static void cx_iter_next_fast(void *it) {
+static void cx_iter_next(void *it) {
     struct cx_iterator_s *iter = it;
-    if (iter->base.remove) {
-        iter->base.remove = false;
-        iter->elem_count--;
-        // only move the last element when we are not currently aiming
-        // at the last element already
-        if (iter->index < iter->elem_count) {
-            void *last = ((char *) iter->src_handle)
-                         + iter->elem_count * iter->elem_size;
-            memcpy(iter->elem_handle, last, iter->elem_size);
-        }
-    } else {
-        iter->index++;
-        iter->elem_handle = ((char *) iter->elem_handle) + iter->elem_size;
-    }
+    assert(!iter->base.remove);
+    iter->index++;
+    iter->elem_handle = ((char *) iter->elem_handle) + iter->elem_size;
 }
 
-static void cx_iter_next_slow(void *it) {
-    struct cx_iterator_s *iter = it;
-    if (iter->base.remove) {
-        iter->base.remove = false;
-        iter->elem_count--;
-
-        // number of elements to move
-        size_t remaining = iter->elem_count - iter->index;
-        if (remaining > 0) {
-            memmove(
-                    iter->elem_handle,
-                    ((char *) iter->elem_handle) + iter->elem_size,
-                    remaining * iter->elem_size
-            );
-        }
-    } else {
-        iter->index++;
-        iter->elem_handle = ((char *) iter->elem_handle) + iter->elem_size;
-    }
-}
-
-CxIterator cxIterator(
-        const void *array,
-        size_t elem_size,
-        size_t elem_count,
-        bool remove_keeps_order
-) {
+CxIterator cxIterator(const void *array, size_t elem_size, size_t elem_count) {
     CxIterator iter;
 
     iter.index = 0;
@@ -99,19 +63,18 @@
     iter.elem_count = array == NULL ? 0 : elem_count;
     iter.base.valid = cx_iter_valid;
     iter.base.current = cx_iter_current;
-    iter.base.next = remove_keeps_order ? cx_iter_next_slow : cx_iter_next_fast;
+    iter.base.next = cx_iter_next;
+    iter.base.valid_impl = NULL;
+    iter.base.current_impl = NULL;
+    iter.base.next_impl = NULL;
     iter.base.remove = false;
     iter.base.allow_remove = true;
 
     return iter;
 }
 
-CxIterator cxIteratorPtr(
-        const void *array,
-        size_t elem_count,
-        bool remove_keeps_order
-) {
-    CxIterator iter = cxIterator(array, sizeof(void*), elem_count, remove_keeps_order);
+CxIterator cxIteratorPtr(const void *array, size_t elem_count) {
+    CxIterator iter = cxIterator(array, sizeof(void*), elem_count);
     iter.base.current = cx_iter_current_ptr;
     return iter;
 }
--- a/ucx/json.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/json.c	Fri Dec 19 17:53:18 2025 +0100
@@ -27,6 +27,7 @@
  */
 
 #include "cx/json.h"
+#include "cx/kv_list.h"
 
 #include <string.h>
 #include <assert.h>
@@ -41,90 +42,10 @@
 
 static CxJsonValue cx_json_value_nothing = {.type = CX_JSON_NOTHING};
 
-static int json_cmp_objvalue(const void *l, const void *r) {
-    const CxJsonObjValue *left = l;
-    const CxJsonObjValue *right = r;
-    return cx_strcmp(cx_strcast(left->name), cx_strcast(right->name));
-}
-
-static size_t json_find_objvalue(const CxJsonValue *obj, cxstring name) {
-    assert(obj->type == CX_JSON_OBJECT);
-    CxJsonObjValue kv_dummy;
-    kv_dummy.name = cx_mutstrn((char*) name.ptr, name.length);
-    return cx_array_binary_search(
-            obj->value.object.values,
-            obj->value.object.values_size,
-            sizeof(CxJsonObjValue),
-            &kv_dummy,
-            json_cmp_objvalue
-    );
-}
-
-static int json_add_objvalue(CxJsonValue *objv, CxJsonObjValue member) {
-    assert(objv->type == CX_JSON_OBJECT);
-    const CxAllocator * const al = objv->allocator;
-    CxJsonObject *obj = &(objv->value.object);
-
-    // determine the index where we need to insert the new member
-    size_t index = cx_array_binary_search_sup(
-        obj->values,
-        obj->values_size,
-        sizeof(CxJsonObjValue),
-        &member, json_cmp_objvalue
-    );
-
-    // is the name already present?
-    if (index < obj->values_size && 0 == json_cmp_objvalue(&member, &obj->values[index])) {
-        // free the original value
-        cx_strfree_a(al, &obj->values[index].name);
-        cxJsonValueFree(obj->values[index].value);
-        // replace the item
-        obj->values[index] = member;
-
-        // nothing more to do
-        return 0;
-    }
-
-    // determine the old capacity and reserve for one more element
-    CxArrayReallocator arealloc = cx_array_reallocator(al, NULL);
-    size_t oldcap = obj->values_capacity;
-    if (cx_array_simple_reserve_a(&arealloc, obj->values, 1)) return 1;
-
-    // check the new capacity, if we need to realloc the index array
-    size_t newcap = obj->values_capacity;
-    if (newcap > oldcap) {
-        if (cxReallocateArray(al, &obj->indices, newcap, sizeof(size_t))) {
-            return 1;
-        }
-    }
-
-    // check if append or insert
-    if (index < obj->values_size) {
-        // move the other elements
-        memmove(
-            &obj->values[index+1],
-            &obj->values[index],
-            (obj->values_size - index) * sizeof(CxJsonObjValue)
-        );
-        // increase indices for the moved elements
-        for (size_t i = 0; i < obj->values_size ; i++) {
-            if (obj->indices[i] >= index) {
-                obj->indices[i]++;
-            }
-        }
-    }
-
-    // insert the element and set the index
-    obj->values[index] = member;
-    obj->indices[obj->values_size] = index;
-    obj->values_size++;
-
-    return 0;
-}
-
 static void token_destroy(CxJsonToken *token) {
     if (token->allocated) {
         cx_strfree(&token->content);
+        token->allocated = false;
     }
 }
 
@@ -190,8 +111,8 @@
         ttype = CX_JSON_TOKEN_STRING;
     } else {
         cxstring s = cx_strcast(str);
-        if (!cx_strcmp(s, CX_STR("true")) || !cx_strcmp(s, CX_STR("false"))
-            || !cx_strcmp(s, CX_STR("null"))) {
+        if (!cx_strcmp(s, "true") || !cx_strcmp(s, "false")
+            || !cx_strcmp(s, "null")) {
             ttype = CX_JSON_TOKEN_LITERAL;
         } else {
             ttype = token_numbertype(str.ptr, str.length);
@@ -307,7 +228,9 @@
         }
     }
 
-    if (ttype != CX_JSON_NO_TOKEN) {
+    if (ttype == CX_JSON_NO_TOKEN) {
+        return CX_JSON_NO_DATA;
+    } else {
         // uncompleted token
         size_t uncompleted_len = json->buffer.size - token_part_start;
         if (json->uncompleted.tokentype == CX_JSON_NO_TOKEN) {
@@ -334,9 +257,8 @@
         }
         // advance the buffer position - we saved the stuff in the uncompleted token
         json->buffer.pos += uncompleted_len;
+        return CX_JSON_INCOMPLETE_DATA;
     }
-
-    return CX_JSON_INCOMPLETE_DATA;
 }
 
 // converts a Unicode codepoint to utf8
@@ -437,7 +359,7 @@
             } else if (c == 'u') {
                 char utf8buf[4];
                 unsigned utf8len = unescape_unicode_string(
-                    cx_strn(str.ptr + i - 1, str.length + 1 - i),
+                    cx_strn(str.ptr + i - 1, str.length - i),
                     utf8buf
                 );
                 if(utf8len > 0) {
@@ -456,7 +378,7 @@
             } else {
                 // TODO: discuss the behavior for unrecognized escape sequences
                 //       most parsers throw an error here - we just ignore it
-                result.ptr[result.length++] = '\\';
+                result.ptr[result.length++] = '\\'; // LCOV_EXCL_LINE
             }
 
             result.ptr[result.length++] = c;
@@ -473,7 +395,7 @@
     return result;
 }
 
-static cxmutstr escape_string(cxmutstr str, bool escape_slash) {
+static cxmutstr escape_string(cxstring str, bool escape_slash) {
     // note: this function produces the string without enclosing quotes
     // the reason is that we don't want to allocate memory just for that
     CxBuffer buf = {0};
@@ -488,7 +410,7 @@
             size_t capa = str.length + 32;
             char *space = cxMallocDefault(capa);
             if (space == NULL) return cx_mutstrn(NULL, 0);
-            cxBufferInit(&buf, space, capa, NULL, CX_BUFFER_AUTO_EXTEND);
+            cxBufferInit(&buf, NULL, space, capa, CX_BUFFER_AUTO_EXTEND);
             cxBufferWrite(str.ptr, 1, i, &buf);
             all_printable = false;
         }
@@ -519,11 +441,27 @@
             cxBufferPut(&buf, c);
         }
     }
-    if (!all_printable) {
-        str = cx_mutstrn(buf.space, buf.size);
+    cxmutstr ret;
+    if (all_printable) {
+        // don't copy the string when we don't need to escape anything
+        ret = cx_mutstrn((char*)str.ptr, str.length);
+    } else {
+        ret = cx_mutstrn(buf.space, buf.size);
     }
     cxBufferDestroy(&buf);
-    return str;
+    return ret;
+}
+
+static CxJsonObject json_create_object_map(const CxAllocator *allocator) {
+    CxMap *map = cxKvListCreateAsMap(allocator, CX_STORE_POINTERS);
+    if (map == NULL) return NULL; // LCOV_EXCL_LINE
+    cxSetCompareFunc(map, cxJsonCompare);
+    cxSetDestructor(map, cxJsonValueFree);
+    return map;
+}
+
+static void json_free_object_map(CxJsonObject obj) {
+    cxMapFree(obj);
 }
 
 static CxJsonValue* json_create_value(CxJson *json, CxJsonValueType type) {
@@ -534,33 +472,30 @@
     v->type = type;
     v->allocator = json->allocator;
     if (type == CX_JSON_ARRAY) {
-        cx_array_initialize_a(json->allocator, v->value.array.array, 16);
-        if (v->value.array.array == NULL) goto create_json_value_exit_error; // LCOV_EXCL_LINE
+        if (cx_array_init_a(json->allocator, v->array, 16)) {
+            goto create_json_value_exit_error; // LCOV_EXCL_LINE
+        }
     } else if (type == CX_JSON_OBJECT) {
-        cx_array_initialize_a(json->allocator, v->value.object.values, 16);
-        v->value.object.indices = cxCalloc(json->allocator, 16, sizeof(size_t));
-        if (v->value.object.values == NULL ||
-            v->value.object.indices == NULL)
-            goto create_json_value_exit_error; // LCOV_EXCL_LINE
+        v->object = json_create_object_map(json->allocator);
+        if (v->object == NULL) goto create_json_value_exit_error; // LCOV_EXCL_LINE
     }
 
     // add the new value to a possible parent
-    if (json->vbuf_size > 0) {
-        CxJsonValue *parent = json->vbuf[json->vbuf_size - 1];
+    if (json->vbuf.size > 0) {
+        CxJsonValue *parent = json->vbuf.data[json->vbuf.size - 1];
         assert(parent != NULL);
         if (parent->type == CX_JSON_ARRAY) {
-            CxArrayReallocator value_realloc = cx_array_reallocator(json->allocator, NULL);
-            if (cx_array_simple_add_a(&value_realloc, parent->value.array.array, v)) {
+            if (cx_array_add_a(json->allocator, parent->array, v)) {
                 goto create_json_value_exit_error; // LCOV_EXCL_LINE
             }
         } else if (parent->type == CX_JSON_OBJECT) {
             // the member was already created after parsing the name
-            assert(json->uncompleted_member.name.ptr != NULL);
-            json->uncompleted_member.value = v;
-            if (json_add_objvalue(parent, json->uncompleted_member))  {
+            // store the pointer of the uncompleted value in the map
+            assert(json->uncompleted_member_name.ptr != NULL);
+            if (cxMapPut(parent->object, json->uncompleted_member_name, v)) {
                 goto create_json_value_exit_error; // LCOV_EXCL_LINE
             }
-            json->uncompleted_member.name = (cxmutstr) {NULL, 0};
+            cx_strfree_a(json->allocator, &json->uncompleted_member_name);
         } else {
             assert(false); // LCOV_EXCL_LINE
         }
@@ -568,10 +503,19 @@
 
     // add the new value to the stack, if it is an array or object
     if (type == CX_JSON_ARRAY || type == CX_JSON_OBJECT) {
-        CxArrayReallocator vbuf_realloc = cx_array_reallocator(NULL, json->vbuf_internal);
-        if (cx_array_simple_add_a(&vbuf_realloc, json->vbuf, v)) {
-            goto create_json_value_exit_error; // LCOV_EXCL_LINE
+        if (json->vbuf.size >= json->vbuf.capacity) {
+            int alloc_error;
+            if (json->vbuf.data == json->vbuf_internal) {
+                alloc_error = cx_array_copy_to_new(json->vbuf, json->vbuf.size+1);
+            } else {
+                alloc_error = cx_array_reserve(json->vbuf, json->vbuf.size+1);
+            }
+            if (alloc_error) {
+                goto create_json_value_exit_error; // LCOV_EXCL_LINE
+            }
         }
+        json->vbuf.data[json->vbuf.size] = v;
+        json->vbuf.size++;
     }
 
     // if currently no value is parsed, this is now the value of interest
@@ -605,29 +549,23 @@
     memset(json, 0, sizeof(CxJson));
     json->allocator = allocator;
 
-    json->states = json->states_internal;
-    json->states_capacity = cx_nmemb(json->states_internal);
-    json->states[0] = JP_STATE_VALUE_BEGIN;
-    json->states_size = 1;
-
-    json->vbuf = json->vbuf_internal;
-    json->vbuf_capacity = cx_nmemb(json->vbuf_internal);
+    cx_array_init_fixed(json->states, json->states_internal, 1);
+    json->states.data[0] = JP_STATE_VALUE_BEGIN;
+    cx_array_init_fixed(json->vbuf, json->vbuf_internal, 0);
 }
 
 void cxJsonDestroy(CxJson *json) {
     cxBufferDestroy(&json->buffer);
-    if (json->states != json->states_internal) {
-        cxFreeDefault(json->states);
+    if (json->states.data != json->states_internal) {
+        cx_array_free(json->states);
     }
-    if (json->vbuf != json->vbuf_internal) {
-        cxFreeDefault(json->vbuf);
+    if (json->vbuf.data != json->vbuf_internal) {
+        cx_array_free(json->vbuf);
     }
     cxJsonValueFree(json->parsed);
     json->parsed = NULL;
-    if (json->uncompleted_member.name.ptr != NULL) {
-        cx_strfree_a(json->allocator, &json->uncompleted_member.name);
-        json->uncompleted_member = (CxJsonObjValue){{NULL, 0}, NULL};
-    }
+    token_destroy(&json->uncompleted);
+    cx_strfree_a(json->allocator, &json->uncompleted_member_name);
 }
 
 void cxJsonReset(CxJson *json) {
@@ -640,8 +578,9 @@
     if (cxBufferEof(&json->buffer)) {
         // reinitialize the buffer
         cxBufferDestroy(&json->buffer);
-        cxBufferInit(&json->buffer, (char*) buf, size,
-            NULL, CX_BUFFER_AUTO_EXTEND | CX_BUFFER_COPY_ON_WRITE);
+        if (buf == NULL) buf = ""; // buffer must not be initialized with NULL
+        cxBufferInit(&json->buffer, NULL, (char*) buf,
+                     size, CX_BUFFER_AUTO_EXTEND | CX_BUFFER_COPY_ON_WRITE);
         json->buffer.size = size;
         return 0;
     } else {
@@ -650,9 +589,9 @@
 }
 
 static void json_add_state(CxJson *json, int state) {
-    // we have guaranteed the necessary space with cx_array_simple_reserve()
+    // we have guaranteed the necessary space
     // therefore, we can safely add the state in the simplest way possible
-    json->states[json->states_size++] = state;
+    json->states.data[json->states.size++] = state;
 }
 
 #define return_rec(code) \
@@ -673,13 +612,21 @@
     }
 
     // pop the current state
-    assert(json->states_size > 0);
-    int state = json->states[--json->states_size];
+    assert(json->states.size > 0);
+    int state = json->states.data[--json->states.size];
 
-    // guarantee that at least two more states fit on the stack
-    CxArrayReallocator state_realloc = cx_array_reallocator(NULL, json->states_internal);
-    if (cx_array_simple_reserve_a(&state_realloc, json->states, 2)) {
-        return CX_JSON_BUFFER_ALLOC_FAILED; // LCOV_EXCL_LINE
+    // guarantee that at least two more states fit into the array
+    const size_t required_states_depth = json->states.size + 2;
+    if (required_states_depth >= json->states.capacity) {
+        int alloc_error;
+        if (json->states.data == json->states_internal) {
+            alloc_error = cx_array_copy_to_new(json->states, required_states_depth);
+        } else {
+            alloc_error = cx_array_reserve(json->states, required_states_depth);
+        }
+        if (alloc_error) {
+            return CX_JSON_BUFFER_ALLOC_FAILED; // LCOV_EXCL_LINE
+        }
     }
 
 
@@ -711,6 +658,16 @@
                 json_add_state(json, JP_STATE_OBJ_NAME_OR_CLOSE);
                 return_rec(CX_JSON_NO_ERROR);
             }
+            case CX_JSON_TOKEN_END_ARRAY: {
+                if (state == JP_STATE_VALUE_BEGIN_AR) {
+                    // discard the array from the value buffer
+                    json->vbuf.size--;
+                    json->states.size--;
+                    return_rec(CX_JSON_NO_ERROR);
+                } else {
+                    return_rec(CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN);
+                }
+            }
             case CX_JSON_TOKEN_STRING: {
                 if ((vbuf = json_create_value(json, CX_JSON_STRING)) == NULL) {
                     return_rec(CX_JSON_VALUE_ALLOC_FAILED); // LCOV_EXCL_LINE
@@ -719,7 +676,7 @@
                 if (str.ptr == NULL) {
                     return_rec(CX_JSON_VALUE_ALLOC_FAILED); // LCOV_EXCL_LINE
                 }
-                vbuf->value.string = str;
+                vbuf->string = str;
                 return_rec(CX_JSON_NO_ERROR);
             }
             case CX_JSON_TOKEN_INTEGER:
@@ -729,12 +686,13 @@
                     return_rec(CX_JSON_VALUE_ALLOC_FAILED); // LCOV_EXCL_LINE
                 }
                 if (type == CX_JSON_INTEGER) {
-                    if (cx_strtoi64(token.content, &vbuf->value.integer, 10)) {
+                    if (cx_strtoi64(token.content, &vbuf->integer, 10)) {
                         return_rec(CX_JSON_FORMAT_ERROR_NUMBER);
                     }
                 } else {
-                    if (cx_strtod(token.content, &vbuf->value.number)) {
-                        return_rec(CX_JSON_FORMAT_ERROR_NUMBER);
+                    if (cx_strtod(token.content, &vbuf->number)) {
+                        // TODO: at the moment this is unreachable, because the tokenizer is already stricter than cx_strtod()
+                        return_rec(CX_JSON_FORMAT_ERROR_NUMBER);  // LCOV_EXCL_LINE
                     }
                 }
                 return_rec(CX_JSON_NO_ERROR);
@@ -743,12 +701,12 @@
                 if ((vbuf = json_create_value(json, CX_JSON_LITERAL)) == NULL) {
                     return_rec(CX_JSON_VALUE_ALLOC_FAILED); // LCOV_EXCL_LINE
                 }
-                if (0 == cx_strcmp(cx_strcast(token.content), cx_str("true"))) {
-                    vbuf->value.literal = CX_JSON_TRUE;
-                } else if (0 == cx_strcmp(cx_strcast(token.content), cx_str("false"))) {
-                    vbuf->value.literal = CX_JSON_FALSE;
+                if (0 == cx_strcmp(token.content, "true")) {
+                    vbuf->literal = CX_JSON_TRUE;
+                } else if (0 == cx_strcmp(token.content, "false")) {
+                    vbuf->literal = CX_JSON_FALSE;
                 } else {
-                    vbuf->value.literal = CX_JSON_NULL;
+                    vbuf->literal = CX_JSON_NULL;
                 }
                 return_rec(CX_JSON_NO_ERROR);
             }
@@ -763,7 +721,7 @@
             return_rec(CX_JSON_NO_ERROR);
         } else if (token.tokentype == CX_JSON_TOKEN_END_ARRAY) {
             // discard the array from the value buffer
-            json->vbuf_size--;
+            json->vbuf.size--;
             return_rec(CX_JSON_NO_ERROR);
         } else {
             return_rec(CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN);
@@ -771,7 +729,7 @@
     } else if (state == JP_STATE_OBJ_NAME_OR_CLOSE || state == JP_STATE_OBJ_NAME) {
         if (state == JP_STATE_OBJ_NAME_OR_CLOSE && token.tokentype == CX_JSON_TOKEN_END_OBJECT) {
             // discard the obj from the value buffer
-            json->vbuf_size--;
+            json->vbuf.size--;
             return_rec(CX_JSON_NO_ERROR);
         } else {
             // expect string
@@ -784,9 +742,9 @@
             if (name.ptr == NULL) {
                 return_rec(CX_JSON_VALUE_ALLOC_FAILED); // LCOV_EXCL_LINE
             }
-            assert(json->uncompleted_member.name.ptr == NULL);
-            json->uncompleted_member.name = name;
-            assert(json->vbuf_size > 0);
+            assert(json->uncompleted_member_name.ptr == NULL);
+            json->uncompleted_member_name = name;
+            assert(json->vbuf.size > 0);
 
             // next state
             json_add_state(json, JP_STATE_OBJ_COLON);
@@ -807,7 +765,7 @@
             return_rec(CX_JSON_NO_ERROR);
         } else if (token.tokentype == CX_JSON_TOKEN_END_OBJECT) {
             // discard the obj from the value buffer
-            json->vbuf_size--;
+            json->vbuf.size--;
             return_rec(CX_JSON_NO_ERROR);
         } else {
             return_rec(CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN);
@@ -815,34 +773,34 @@
     } else {
         // should be unreachable
         assert(false);
-        return_rec(-1);
+        return_rec(-1); // LCOV_EXCL_LINE
     }
 }
 
 CxJsonStatus cxJsonNext(CxJson *json, CxJsonValue **value) {
-    // check if buffer has been filled
+    // initialize output value
+    *value = &cx_json_value_nothing;
+
+    // check if the buffer has been filled
     if (json->buffer.space == NULL) {
         return CX_JSON_NULL_DATA;
     }
 
-    // initialize output value
-    *value = &cx_json_value_nothing;
-
     // parse data
     CxJsonStatus result;
     do {
         result = json_parse(json);
-        if (result == CX_JSON_NO_ERROR && json->states_size == 1) {
+        if (result == CX_JSON_NO_ERROR && json->states.size == 1) {
             // final state reached
-            assert(json->states[0] == JP_STATE_VALUE_END);
-            assert(json->vbuf_size == 0);
+            assert(json->states.data[0] == JP_STATE_VALUE_END);
+            assert(json->vbuf.size == 0);
 
             // write output value
             *value = json->parsed;
             json->parsed = NULL;
 
             // re-initialize state machine
-            json->states[0] = JP_STATE_VALUE_BEGIN;
+            json->states.data[0] = JP_STATE_VALUE_BEGIN;
 
             return CX_JSON_NO_ERROR;
         }
@@ -851,36 +809,60 @@
     // the parser might think there is no data
     // but when we did not reach the final state,
     // we know that there must be more to come
-    if (result == CX_JSON_NO_DATA && json->states_size > 1) {
+    if (result == CX_JSON_NO_DATA && json->states.size > 1) {
         return CX_JSON_INCOMPLETE_DATA;
     }
 
     return result;
 }
 
+CxJsonStatus cx_json_from_string(const CxAllocator *allocator,
+            cxstring str, CxJsonValue **value) {
+    *value = &cx_json_value_nothing;
+    CxJson parser;
+    cxJsonInit(&parser, allocator);
+    if (cxJsonFill(&parser, str)) {
+        // LCOV_EXCL_START
+        cxJsonDestroy(&parser);
+        return CX_JSON_BUFFER_ALLOC_FAILED;
+        // LCOV_EXCL_STOP
+    }
+    CxJsonStatus status = cxJsonNext(&parser, value);
+    // check if we consume the total string
+    CxJsonValue *chk_value = NULL;
+    CxJsonStatus chk_status = CX_JSON_NO_DATA;
+    if (status == CX_JSON_NO_ERROR) {
+        chk_status = cxJsonNext(&parser, &chk_value);
+    }
+    cxJsonDestroy(&parser);
+    if (chk_status == CX_JSON_NO_DATA) {
+        return status;
+    } else {
+        cxJsonValueFree(*value);
+        // if chk_value is nothing, the free is harmless
+        cxJsonValueFree(chk_value);
+        *value = &cx_json_value_nothing;
+        return CX_JSON_FORMAT_ERROR_UNEXPECTED_TOKEN;
+    }
+
+}
+
 void cxJsonValueFree(CxJsonValue *value) {
     if (value == NULL || value->type == CX_JSON_NOTHING) return;
     switch (value->type) {
         case CX_JSON_OBJECT: {
-            CxJsonObject obj = value->value.object;
-            for (size_t i = 0; i < obj.values_size; i++) {
-                cxJsonValueFree(obj.values[i].value);
-                cx_strfree_a(value->allocator, &obj.values[i].name);
-            }
-            cxFree(value->allocator, obj.values);
-            cxFree(value->allocator, obj.indices);
+            json_free_object_map(value->object);
             break;
         }
         case CX_JSON_ARRAY: {
-            CxJsonArray array = value->value.array;
-            for (size_t i = 0; i < array.array_size; i++) {
-                cxJsonValueFree(array.array[i]);
+            for (size_t i = 0; i < value->array.size; i++) {
+                cxJsonValueFree(value->array.data[i]);
             }
-            cxFree(value->allocator, array.array);
+            cx_array_free_a(value->allocator, value->array);
             break;
         }
         case CX_JSON_STRING: {
-            cxFree(value->allocator, value->value.string.ptr);
+            cxFree(value->allocator, value->string.ptr);
             break;
         }
         default: {
@@ -896,15 +878,8 @@
     if (v == NULL) return NULL;
     v->allocator = allocator;
     v->type = CX_JSON_OBJECT;
-    cx_array_initialize_a(allocator, v->value.object.values, 16);
-    if (v->value.object.values == NULL) { // LCOV_EXCL_START
-        cxFree(allocator, v);
-        return NULL;
-        // LCOV_EXCL_STOP
-    }
-    v->value.object.indices = cxCalloc(allocator, 16, sizeof(size_t));
-    if (v->value.object.indices == NULL) { // LCOV_EXCL_START
-        cxFree(allocator, v->value.object.values);
+    v->object = json_create_object_map(allocator);
+    if (v->object == NULL) { // LCOV_EXCL_START
         cxFree(allocator, v);
         return NULL;
         // LCOV_EXCL_STOP
@@ -912,14 +887,23 @@
     return v;
 }
 
-CxJsonValue* cxJsonCreateArr(const CxAllocator* allocator) {
+CxJsonValue* cxJsonCreateArr(const CxAllocator* allocator, size_t capacity) {
     if (allocator == NULL) allocator = cxDefaultAllocator;
     CxJsonValue* v = cxMalloc(allocator, sizeof(CxJsonValue));
     if (v == NULL) return NULL;
     v->allocator = allocator;
     v->type = CX_JSON_ARRAY;
-    cx_array_initialize_a(allocator, v->value.array.array, 16);
-    if (v->value.array.array == NULL) { cxFree(allocator, v); return NULL; }
+    if (capacity > 0) {
+        if (cx_array_init_a(allocator, v->array, capacity)) {
+            // LCOV_EXCL_START
+            cxFree(allocator, v);
+            return NULL;
+            // LCOV_EXCL_STOP
+        }
+    } else {
+        v->array.data = NULL;
+        v->array.size = v->array.capacity = 0;
+    }
     return v;
 }
 
@@ -929,7 +913,7 @@
     if (v == NULL) return NULL;
     v->allocator = allocator;
     v->type = CX_JSON_NUMBER;
-    v->value.number = num;
+    v->number = num;
     return v;
 }
 
@@ -939,15 +923,11 @@
     if (v == NULL) return NULL;
     v->allocator = allocator;
     v->type = CX_JSON_INTEGER;
-    v->value.integer = num;
+    v->integer = num;
     return v;
 }
 
-CxJsonValue* cxJsonCreateString(const CxAllocator* allocator, const char* str) {
-    return cxJsonCreateCxString(allocator, cx_str(str));
-}
-
-CxJsonValue* cxJsonCreateCxString(const CxAllocator* allocator, cxstring str) {
+CxJsonValue* cx_json_create_string(const CxAllocator* allocator, cxstring str) {
     if (allocator == NULL) allocator = cxDefaultAllocator;
     CxJsonValue* v = cxMalloc(allocator, sizeof(CxJsonValue));
     if (v == NULL) return NULL;
@@ -955,7 +935,7 @@
     v->type = CX_JSON_STRING;
     cxmutstr s = cx_strdup_a(allocator, str);
     if (s.ptr == NULL) { cxFree(allocator, v); return NULL; }
-    v->value.string = s;
+    v->string = s;
     return v;
 }
 
@@ -965,7 +945,7 @@
     if (v == NULL) return NULL;
     v->allocator = allocator;
     v->type = CX_JSON_LITERAL;
-    v->value.literal = lit;
+    v->literal = lit;
     return v;
 }
 
@@ -1020,7 +1000,7 @@
     CxJsonValue** values = cxCallocDefault(count, sizeof(CxJsonValue*));
     if (values == NULL) return -1;
     for (size_t i = 0; i < count; i++) {
-        values[i] = cxJsonCreateCxString(arr->allocator, str[i]);
+        values[i] = cxJsonCreateString(arr->allocator, str[i]);
         if (values[i] == NULL) { json_arr_free_temp(values, count); return -1; }
     }
     int ret = cxJsonArrAddValues(arr, values, count);
@@ -1041,70 +1021,50 @@
 }
 
 int cxJsonArrAddValues(CxJsonValue* arr, CxJsonValue* const* val, size_t count) {
-    CxArrayReallocator value_realloc = cx_array_reallocator(arr->allocator, NULL);
     assert(arr->type == CX_JSON_ARRAY);
-    return cx_array_simple_copy_a(&value_realloc,
-            arr->value.array.array,
-            arr->value.array.array_size,
-            val, count
-    );
+    return cx_array_add_array_a(arr->allocator, arr->array, val, count);
 }
 
-int cxJsonObjPut(CxJsonValue* obj, cxstring name, CxJsonValue* child) {
-    cxmutstr k = cx_strdup_a(obj->allocator, name);
-    if (k.ptr == NULL) return -1;
-    CxJsonObjValue kv = {k, child};
-    if (json_add_objvalue(obj, kv)) {
-        cx_strfree_a(obj->allocator, &k);
-        return 1;
-    } else {
-        return 0;
-    }
+int cx_json_obj_put(CxJsonValue* obj, cxstring name, CxJsonValue* child) {
+    return cxMapPut(obj->object, name, child);
 }
 
-CxJsonValue* cxJsonObjPutObj(CxJsonValue* obj, cxstring name) {
+CxJsonValue* cx_json_obj_put_obj(CxJsonValue* obj, cxstring name) {
     CxJsonValue* v = cxJsonCreateObj(obj->allocator);
     if (v == NULL) return NULL;
     if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL; }
     return v;
 }
 
-CxJsonValue* cxJsonObjPutArr(CxJsonValue* obj, cxstring name) {
-    CxJsonValue* v = cxJsonCreateArr(obj->allocator);
+CxJsonValue* cx_json_obj_put_arr(CxJsonValue* obj, cxstring name, size_t capacity) {
+    CxJsonValue* v = cxJsonCreateArr(obj->allocator, capacity);
     if (v == NULL) return NULL;
     if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL; }
     return v;
 }
 
-CxJsonValue* cxJsonObjPutNumber(CxJsonValue* obj, cxstring name, double num) {
+CxJsonValue* cx_json_obj_put_number(CxJsonValue* obj, cxstring name, double num) {
     CxJsonValue* v = cxJsonCreateNumber(obj->allocator, num);
     if (v == NULL) return NULL;
     if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL; }
     return v;
 }
 
-CxJsonValue* cxJsonObjPutInteger(CxJsonValue* obj, cxstring name, int64_t num) {
+CxJsonValue* cx_json_obj_put_integer(CxJsonValue* obj, cxstring name, int64_t num) {
     CxJsonValue* v = cxJsonCreateInteger(obj->allocator, num);
     if (v == NULL) return NULL;
     if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL; }
     return v;
 }
 
-CxJsonValue* cxJsonObjPutString(CxJsonValue* obj, cxstring name, const char* str) {
+CxJsonValue* cx_json_obj_put_string(CxJsonValue* obj, cxstring name, cxstring str) {
     CxJsonValue* v = cxJsonCreateString(obj->allocator, str);
     if (v == NULL) return NULL;
     if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL; }
     return v;
 }
 
-CxJsonValue* cxJsonObjPutCxString(CxJsonValue* obj, cxstring name, cxstring str) {
-    CxJsonValue* v = cxJsonCreateCxString(obj->allocator, str);
-    if (v == NULL) return NULL;
-    if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL; }
-    return v;
-}
-
-CxJsonValue* cxJsonObjPutLiteral(CxJsonValue* obj, cxstring name, CxJsonLiteral lit) {
+CxJsonValue* cx_json_obj_put_literal(CxJsonValue* obj, cxstring name, CxJsonLiteral lit) {
     CxJsonValue* v = cxJsonCreateLiteral(obj->allocator, lit);
     if (v == NULL) return NULL;
     if (cxJsonObjPut(obj, name, v)) { cxJsonValueFree(v); return NULL;}
@@ -1112,98 +1072,75 @@
 }
 
 CxJsonValue *cxJsonArrGet(const CxJsonValue *value, size_t index) {
-    if (index >= value->value.array.array_size) {
+    if (index >= value->array.size) {
         return &cx_json_value_nothing;
     }
-    return value->value.array.array[index];
+    return value->array.data[index];
 }
 
 CxJsonValue *cxJsonArrRemove(CxJsonValue *value, size_t index) {
-    if (index >= value->value.array.array_size) {
+    if (index >= value->array.size) {
         return NULL;
     }
-    CxJsonValue *ret = value->value.array.array[index];
-    // TODO: replace with a low level cx_array_remove()
-    size_t count = value->value.array.array_size - index - 1;
-    if (count > 0) {
-        memmove(value->value.array.array + index, value->value.array.array + index + 1, count * sizeof(CxJsonValue*));
-    }
-    value->value.array.array_size--;
+    CxJsonValue *ret = value->array.data[index];
+    cx_array_remove(value->array, index);
     return ret;
 }
 
 char *cxJsonAsString(const CxJsonValue *value) {
-    return value->value.string.ptr;
+    return value->string.ptr;
 }
 
 cxstring cxJsonAsCxString(const CxJsonValue *value) {
-    return cx_strcast(value->value.string);
+    return cx_strcast(value->string);
 }
 
 cxmutstr cxJsonAsCxMutStr(const CxJsonValue *value) {
-    return value->value.string;
+    return value->string;
 }
 
 double cxJsonAsDouble(const CxJsonValue *value) {
     if (value->type == CX_JSON_INTEGER) {
-        return (double) value->value.integer;
+        return (double) value->integer;
     } else {
-        return value->value.number;
+        return value->number;
     }
 }
 
 int64_t cxJsonAsInteger(const CxJsonValue *value) {
     if (value->type == CX_JSON_INTEGER) {
-        return value->value.integer;
+        return value->integer;
     } else {
-        return (int64_t) value->value.number;
+        return (int64_t) value->number;
     }
 }
 
 CxIterator cxJsonArrIter(const CxJsonValue *value) {
-    return cxIteratorPtr(
-        value->value.array.array,
-        value->value.array.array_size,
-        true // arrays need to keep order
-    );
+    return cx_array_iterator_ptr(value->array);
 }
 
-CxIterator cxJsonObjIter(const CxJsonValue *value) {
-    return cxIterator(
-        value->value.object.values,
-        sizeof(CxJsonObjValue),
-        value->value.object.values_size,
-        true // TODO: objects do not always need to keep order
-    );
+CxMapIterator cxJsonObjIter(const CxJsonValue *value) {
+    return cxMapIterator(value->object);
 }
 
 CxJsonValue *cx_json_obj_get(const CxJsonValue *value, cxstring name) {
-    size_t index = json_find_objvalue(value, name);
-    if (index >= value->value.object.values_size) {
+    CxJsonValue *v = cxMapGet(value->object, name);
+    if (v == NULL) {
         return &cx_json_value_nothing;
     } else {
-        return value->value.object.values[index].value;
+        return v;
     }
 }
 
 CxJsonValue *cx_json_obj_remove(CxJsonValue *value, cxstring name) {
-    size_t index = json_find_objvalue(value, name);
-    if (index >= value->value.object.values_size) {
-        return NULL;
-    } else {
-        CxJsonObjValue kv = value->value.object.values[index];
-        cx_strfree_a(value->allocator, &kv.name);
-        // TODO: replace with cx_array_remove() / cx_array_remove_fast()
-        value->value.object.values_size--;
-        memmove(value->value.object.values + index, value->value.object.values + index + 1, (value->value.object.values_size - index) * sizeof(CxJsonObjValue));
-        return kv.value;
-    }
+    CxJsonValue *v = NULL;
+    cxMapRemoveAndGet(value->object, name, &v);
+    return v;
 }
 
 CxJsonWriter cxJsonWriterCompact(void) {
     return (CxJsonWriter) {
         false,
-        true,
         6,
         false,
         4,
@@ -1214,7 +1151,6 @@
 CxJsonWriter cxJsonWriterPretty(bool use_spaces) {
     return (CxJsonWriter) {
         true,
-        true,
         6,
         use_spaces,
         4,
@@ -1279,17 +1215,8 @@
                 expected++;
             }
             depth++;
-            size_t elem_count = value->value.object.values_size;
-            for (size_t look_idx = 0; look_idx < elem_count; look_idx++) {
-                // get the member either via index array or directly
-                size_t elem_idx = settings->sort_members
-                                      ? look_idx
-                                      : value->value.object.indices[look_idx];
-                CxJsonObjValue *member = &value->value.object.values[elem_idx];
-                if (settings->sort_members) {
-                    depth++;depth--;
-                }
-
+            CxMapIterator member_iter = cxJsonObjIter(value);
+            cx_foreach(const CxMapEntry *, member, member_iter) {
                 // possible indentation
                 if (settings->pretty) {
                     if (cx_json_writer_indent(target, wfunc, settings, depth)) {
@@ -1299,26 +1226,27 @@
 
                 // the name
                 actual += wfunc("\"", 1, 1, target);
-                cxmutstr name = escape_string(member->name, settings->escape_slash);
+                cxstring key = cx_strn(member->key->data, member->key->len);
+                cxmutstr name = escape_string(key, settings->escape_slash);
                 actual += wfunc(name.ptr, 1, name.length, target);
-                if (name.ptr != member->name.ptr) {
-                    cx_strfree(&name);
-                }
                 actual += wfunc("\"", 1, 1, target);
                 const char *obj_name_sep = ": ";
                 if (settings->pretty) {
                     actual += wfunc(obj_name_sep, 1, 2, target);
-                    expected += 4 + member->name.length;
+                    expected += 4 + name.length;
                 } else {
                     actual += wfunc(obj_name_sep, 1, 1, target);
-                    expected += 3 + member->name.length;
+                    expected += 3 + name.length;
+                }
+                if (name.ptr != key.ptr) {
+                    cx_strfree(&name);
                 }
 
                 // the value
                 if (cx_json_write_rec(target, member->value, wfunc, settings, depth)) return 1;
 
                 // end of object-value
-                if (look_idx < elem_count - 1) {
+                if (member_iter.index < member_iter.elem_count - 1) {
                     const char *obj_value_sep = ",\n";
                     if (settings->pretty) {
                         actual += wfunc(obj_value_sep, 1, 2, target);
@@ -1350,7 +1278,9 @@
                 if (cx_json_write_rec(
                         target, element,
                         wfunc, settings, depth)
-                ) return 1;
+                ) {
+                    return 1; // LCOV_EXCL_LINE
+                }
 
                 if (iter.index < iter.elem_count - 1) {
                     const char *arr_value_sep = ", ";
@@ -1369,13 +1299,14 @@
         }
         case CX_JSON_STRING: {
             actual += wfunc("\"", 1, 1, target);
-            cxmutstr str = escape_string(value->value.string, settings->escape_slash);
+            cxmutstr str = escape_string(cx_strcast(value->string),
+                settings->escape_slash);
             actual += wfunc(str.ptr, 1, str.length, target);
-            if (str.ptr != value->value.string.ptr) {
+            actual += wfunc("\"", 1, 1, target);
+            expected += 2 + str.length;
+            if (str.ptr != value->string.ptr) {
                 cx_strfree(&str);
             }
-            actual += wfunc("\"", 1, 1, target);
-            expected += 2 + value->value.string.length;
             break;
         }
         case CX_JSON_NUMBER: {
@@ -1383,7 +1314,7 @@
             // because of the way how %g is defined, we need to
             // double the precision and truncate ourselves
             precision = 1 + (precision > 15 ? 30 : 2 * precision);
-            snprintf(numbuf, 40, "%.*g", precision, value->value.number);
+            snprintf(numbuf, 40, "%.*g", precision, value->number);
             char *dot, *exp;
             unsigned char max_digits;
             // find the decimal separator and hope that it's one of . or ,
@@ -1447,17 +1378,17 @@
             break;
         }
         case CX_JSON_INTEGER: {
-            snprintf(numbuf, 32, "%" PRIi64, value->value.integer);
+            snprintf(numbuf, 32, "%" PRIi64, value->integer);
             size_t len = strlen(numbuf);
             actual += wfunc(numbuf, 1, len, target);
             expected += len;
             break;
         }
         case CX_JSON_LITERAL: {
-            if (value->value.literal == CX_JSON_TRUE) {
+            if (value->literal == CX_JSON_TRUE) {
                 actual += wfunc("true", 1, 4, target);
                 expected += 4;
-            } else if (value->value.literal == CX_JSON_FALSE) {
+            } else if (value->literal == CX_JSON_FALSE) {
                 actual += wfunc("false", 1, 5, target);
                 expected += 5;
             } else {
@@ -1495,3 +1426,144 @@
     }
     return cx_json_write_rec(target, value, wfunc, settings, 0);
 }
+
+static cxmutstr cx_json_to_string(CxJsonValue *value, const CxAllocator *allocator, CxJsonWriter *writer) {
+    if (allocator == NULL) allocator = cxDefaultAllocator;
+    CxBuffer buffer;
+    if (cxBufferInit(&buffer, allocator, NULL, 128,
+                     CX_BUFFER_AUTO_EXTEND | CX_BUFFER_DO_NOT_FREE)) {
+        return (cxmutstr){NULL, 0};
+    }
+    if (cx_json_write_rec(&buffer, value, cxBufferWriteFunc, writer, 0)
+            || cxBufferTerminate(&buffer)) {
+        // LCOV_EXCL_START
+        buffer.flags &= ~CX_BUFFER_DO_NOT_FREE;
+        cxBufferDestroy(&buffer);
+        return (cxmutstr){NULL, 0};
+        // LCOV_EXCL_STOP
+    } else {
+        cxmutstr str = cx_mutstrn(buffer.space, buffer.size);
+        cxBufferDestroy(&buffer);
+        return str;
+    }
+
+}
+
+cxmutstr cxJsonToString(const CxAllocator *allocator, CxJsonValue *value) {
+    CxJsonWriter writer = cxJsonWriterCompact();
+    return cx_json_to_string(value, allocator, &writer);
+}
+
+cxmutstr cxJsonToPrettyString(const CxAllocator *allocator, CxJsonValue *value) {
+    CxJsonWriter writer = cxJsonWriterPretty(true);
+    return cx_json_to_string(value, allocator, &writer);
+}
+
+int cxJsonCompare(const CxJsonValue *json, const CxJsonValue *other) {
+    if (json == other) return 0;
+    if (json == NULL || other == NULL) return -1;
+    if (json->type != other->type) {
+        if (!cxJsonIsNumber(json)) return -1;
+        if (!cxJsonIsNumber(other)) return -1;
+    }
+    switch (json->type) {
+        case CX_JSON_NOTHING:
+            return 0;
+        case CX_JSON_OBJECT:
+            return cxMapCompare(json->object, other->object);
+        case CX_JSON_ARRAY:
+            if (json->array.size != other->array.size) return -1;
+            for (size_t i = 0; i < json->array.size; i++) {
+                const int d = cxJsonCompare(json->array.data[i], other->array.data[i]);
+                if (d != 0) return d;
+            }
+            return 0;
+        case CX_JSON_STRING:
+            return cx_strcmp(json->string, other->string);
+        case CX_JSON_INTEGER:
+            if (other->type == CX_JSON_INTEGER) {
+                return cx_vcmp_int64(json->integer, other->integer);
+            } else {
+                return cx_vcmp_double(cxJsonAsDouble(json), other->number);
+            }
+        case CX_JSON_NUMBER:
+            return cx_vcmp_double(json->number, cxJsonAsDouble(other));
+        case CX_JSON_LITERAL:
+            return json->literal == other->literal ? 0 : -1;
+        default:
+            // LCOV_EXCL_START
+            // unreachable
+            assert(false);
+            return -1;
+            // LCOV_EXCL_STOP
+    }
+}
+
+CxJsonValue* cxJsonClone(const CxJsonValue* value, const CxAllocator* allocator) {
+    return cx_json_clone_func(NULL, value, allocator, NULL);
+}
+
+CxJsonValue* cx_json_clone_func(CxJsonValue* target, const CxJsonValue* source,
+        const CxAllocator* allocator, cx_attr_unused void *data) {
+    if (source == NULL || source->type == CX_JSON_NOTHING) {
+        return &cx_json_value_nothing;
+    }
+    if (allocator == NULL) allocator = cxDefaultAllocator;
+
+#define return_value(v) { \
+        CxJsonValue *ret = v; \
+        if (target == NULL) { \
+            return ret; \
+        } else { \
+            *target = *ret; \
+            cxFree(allocator, ret); \
+            return target; \
+        } \
+    }
+
+    switch (source->type) {
+        case CX_JSON_OBJECT: {
+            CxJsonValue *obj = cxJsonCreateObj(allocator);
+            if (obj == NULL) return NULL; // LCOV_EXCL_LINE
+            if (cxMapClone(obj->object, source->object, cxJsonCloneFunc, allocator, NULL)) {
+                // LCOV_EXCL_START
+                cxJsonValueFree(obj);
+                return NULL;
+                // LCOV_EXCL_STOP
+            }
+            return_value(obj);
+        }
+        case CX_JSON_ARRAY: {
+            const size_t elem_count = source->array.size;
+            CxJsonValue *arr = cxJsonCreateArr(allocator, elem_count);
+            if (arr == NULL) return NULL; // LCOV_EXCL_LINE
+            arr->array.size = elem_count;
+            for (size_t i = 0 ; i < elem_count ; i++) {
+                CxJsonValue *e = cx_json_clone_func(NULL, source->array.data[i], allocator, NULL);
+                if (e == NULL) {
+                    // LCOV_EXCL_START
+                    cxJsonValueFree(arr);
+                    return NULL;
+                    // LCOV_EXCL_STOP
+                }
+                arr->array.data[i] = e;
+            }
+            return_value(arr);
+        }
+        case CX_JSON_STRING:
+            return_value(cxJsonCreateString(allocator, source->string));
+        case CX_JSON_INTEGER:
+            return_value(cxJsonCreateInteger(allocator, source->integer));
+        case CX_JSON_NUMBER:
+            return_value(cxJsonCreateNumber(allocator, source->number));
+        case CX_JSON_LITERAL:
+            return_value(cxJsonCreateLiteral(allocator, source->literal));
+        default:
+            // LCOV_EXCL_START
+            // unreachable
+            assert(false);
+            return NULL;
+            // LCOV_EXCL_STOP
+    }
+#undef return_value
+}
--- a/ucx/kv_list.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/kv_list.c	Fri Dec 19 17:53:18 2025 +0100
@@ -98,7 +98,7 @@
 }
 
 static CxHashKey *cx_kv_list_loc_key(cx_kv_list *list, void *node_data) {
-    return (CxHashKey*)((char*)node_data + list->list.base.collection.elem_size);
+    return (CxHashKey*)((char*)node_data - list->list.loc_data + list->list.loc_extra);
 }
 
 static void cx_kvl_deallocate(struct cx_list_s *list) {
@@ -221,11 +221,12 @@
 
     size_t index;
     cx_linked_list *ll = &kv_list->list;
-    char *node = cx_linked_list_find(
+    char *node = cx_linked_list_find_c(
             ll->begin,
             ll->loc_next, ll->loc_data,
-            list->collection.cmpfunc, elem,
-            &index
+            elem, &index,
+            cx_list_compare_wrapper,
+            list
     );
     if (node == NULL) {
         return list->collection.size;
@@ -285,6 +286,7 @@
 
 static void cx_kvl_map_deallocate(struct cx_map_s *map) {
     cx_kv_list *kv_list = ((struct cx_kv_list_map_s*)map)->list;
+    cx_kv_list_update_destructors(kv_list);
     kv_list->map_methods->deallocate(map);
     kv_list->list_methods->deallocate(&kv_list->list.base);
 }
@@ -296,41 +298,7 @@
     kv_list->map_methods->clear(map);
 }
 
-static void *cx_kvl_map_put(CxMap *map, CxHashKey key, void *value) {
-    cx_kv_list *kv_list = ((struct cx_kv_list_map_s*)map)->list;
-    // if the hash has not yet been computed, do it now
-    if (key.hash == 0) {
-        cx_hash_murmur(&key);
-    }
-
-    // reserve memory in the map first
-    void **map_data = kv_list->map_methods->put(map, key, NULL);
-    if (map_data == NULL) return NULL; // LCOV_EXCL_LINE
-
-    // insert the data into the list (which most likely destroys the sorted property)
-    kv_list->list.base.collection.sorted = false;
-    void *node_data = kv_list->list_methods->insert_element(
-        &kv_list->list.base, kv_list->list.base.collection.size,
-        kv_list->list.base.collection.store_pointer ? &value : value);
-    if (node_data == NULL) { // LCOV_EXCL_START
-        // non-destructively remove the key again
-        kv_list->map_methods->remove(&kv_list->map->map_base.base, key, &map_data);
-        return NULL;
-    } // LCOV_EXCL_STOP
-
-    // write the node pointer to the map entry
-    *map_data = node_data;
-
-    // copy the key to the node data
-    CxHashKey *key_ptr = cx_kv_list_loc_key(kv_list, node_data);
-    *key_ptr = key;
-
-    // we must return node_data here and not map_data,
-    // because the node_data is the actual element of this collection
-    return node_data;
-}
-
-void *cx_kvl_map_get(const CxMap *map, CxHashKey key) {
+static void *cx_kvl_map_get(const CxMap *map, CxHashKey key) {
     cx_kv_list *kv_list = ((struct cx_kv_list_map_s*)map)->list;
     void *node_data = kv_list->map_methods->get(map, key);
     if (node_data == NULL) return NULL; // LCOV_EXCL_LINE
@@ -338,7 +306,7 @@
     return kv_list->list.base.collection.store_pointer ? *(void**)node_data : node_data;
 }
 
-int cx_kvl_map_remove(CxMap *map, CxHashKey key, void *targetbuf) {
+static int cx_kvl_map_remove(CxMap *map, CxHashKey key, void *targetbuf) {
     cx_kv_list *kv_list = ((struct cx_kv_list_map_s*)map)->list;
 
     void *node_data;
@@ -381,6 +349,43 @@
     return 0;
 }
 
+static CxMapEntry cx_kvl_map_put(CxMap *map, CxHashKey key, void *value) {
+    cx_kv_list *kv_list = ((struct cx_kv_list_map_s*)map)->list;
+    // if the hash has not yet been computed, do it now
+    if (key.hash == 0) {
+        cx_hash_murmur(&key);
+    }
+
+    // remove any existing element first
+    cx_kvl_map_remove(map, key, NULL);
+
+    // now reserve new memory in the map
+    CxMapEntry map_entry = kv_list->map_methods->put(map, key, NULL);
+    if (map_entry.key == NULL) return (CxMapEntry){NULL, NULL}; // LCOV_EXCL_LINE
+
+    // insert the data into the list (which most likely destroys the sorted property)
+    kv_list->list.base.collection.sorted = false;
+    void *node_data = kv_list->list_methods->insert_element(
+        &kv_list->list.base, kv_list->list.base.collection.size,
+        kv_list->list.base.collection.store_pointer ? &value : value);
+    if (node_data == NULL) { // LCOV_EXCL_START
+        // non-destructively remove the key again
+        void *dummy;
+        kv_list->map_methods->remove(&kv_list->map->map_base.base, key, &dummy);
+        return (CxMapEntry){NULL, NULL};
+    } // LCOV_EXCL_STOP
+
+    // write the node pointer to the map entry
+    *(void**)map_entry.value = node_data;
+
+    // copy the key to the node data
+    CxHashKey *key_ptr = cx_kv_list_loc_key(kv_list, node_data);
+    *key_ptr = *map_entry.key;
+
+    // we must return an entry that points to the node data!
+    return (CxMapEntry ){key_ptr, node_data};
+}
+
 static void *cx_kvl_iter_current_entry(const void *it) {
     const CxMapIterator *iter = it;
     return (void*)&iter->entry;
@@ -455,7 +460,7 @@
     return iter->elem != NULL;
 }
 
-CxMapIterator cx_kvl_map_iterator(const CxMap *map, enum cx_map_iterator_type type) {
+static CxMapIterator cx_kvl_map_iterator(const CxMap *map, enum cx_map_iterator_type type) {
     CxMapIterator iter = {0};
 
     iter.type = type;
@@ -509,6 +514,15 @@
     return iter;
 }
 
+static int cx_kvl_change_capacity(struct cx_list_s *list,
+        cx_attr_unused size_t cap) {
+    // since our backing list is a linked list, we don't need to do much here,
+    // but rehashing the map is quite useful
+    cx_kv_list *kv_list = (cx_kv_list*)list;
+    cxMapRehash(&kv_list->map->map_base.base);
+    return 0;
+}
+
 static cx_list_class cx_kv_list_class = {
     cx_kvl_deallocate,
     cx_kvl_insert_element,
@@ -524,6 +538,7 @@
     cx_kvl_sort,
     NULL,
     cx_kvl_reverse,
+    cx_kvl_change_capacity,
     cx_kvl_iterator,
 };
 
@@ -538,7 +553,6 @@
 
 CxList *cxKvListCreate(
         const CxAllocator *allocator,
-        cx_compare_func comparator,
         size_t elem_size
 ) {
     if (allocator == NULL) {
@@ -546,10 +560,10 @@
     }
 
     // create a normal linked list and a normal hash map, first
-    CxList *list = cxLinkedListCreate(allocator, comparator, elem_size);
+    CxList *list = cxLinkedListCreate(allocator, elem_size);
     if (list == NULL) return NULL; // LCOV_EXCL_LINE
     cx_linked_list *ll = (cx_linked_list*)list;
-    ll->extra_data_len = sizeof(CxHashKey);
+    cx_linked_list_extra_data(ll, sizeof(CxHashKey));
     CxMap *map = cxHashMapCreate(allocator, CX_STORE_POINTERS, 0);
     if (map == NULL) { // LCOV_EXCL_START
         cxListFree(list);
@@ -586,23 +600,17 @@
     // remember the base methods and override them
     kv_list->map_methods = map->cl;
     map->cl = &cx_kv_map_class;
-    if (list->climpl == NULL) {
-        kv_list->list_methods = list->cl;
-        list->cl = &cx_kv_list_class;
-    } else {
-        kv_list->list_methods = list->climpl;
-        list->climpl = &cx_kv_list_class;
-    }
+    kv_list->list_methods = list->cl;
+    list->cl = &cx_kv_list_class;
 
     return list;
 }
 
 CxMap *cxKvListCreateAsMap(
         const CxAllocator *allocator,
-        cx_compare_func comparator,
         size_t elem_size
 ) {
-    CxList *list = cxKvListCreate(allocator, comparator, elem_size);
+    CxList *list = cxKvListCreate(allocator, elem_size);
     return list == NULL ? NULL : cxKvListAsMap(list);
 }
 
@@ -635,14 +643,14 @@
         return 1;
     }
 
-    // add the key to the map;
-    if (NULL == kv_list->map_methods->put(&kv_list->map->map_base.base, key, node_data)) {
-        return 1; // LCOV_EXCL_LINE
-    }
+    // add the key to the map
+    const CxMapEntry entry = kv_list->map_methods->put(
+            &kv_list->map->map_base.base, key, node_data);
+    if (entry.key == NULL) return 1; // LCOV_EXCL_LINE
 
     // write the key to the list's node
     CxHashKey *loc_key = cx_kv_list_loc_key(kv_list, node_data);
-    *loc_key = key;
+    *loc_key = *entry.key;
 
     return 0;
 }
@@ -684,22 +692,23 @@
     cx_kv_list *kv_list = (cx_kv_list*)list;
 
     // reserve memory in the map
-    void **map_data = kv_list->map_methods->put(&kv_list->map->map_base.base, key, NULL);
-    if (map_data == NULL) return 1; // LCOV_EXCL_LINE
+    CxMapEntry map_entry = kv_list->map_methods->put(&kv_list->map->map_base.base, key, NULL);
+    if (map_entry.key == NULL) return 1; // LCOV_EXCL_LINE
 
     // insert the node
     void *node_data = kv_list->list_methods->insert_element(&kv_list->list.base, index,
         kv_list->list.base.collection.store_pointer ? &value : value);
     if (node_data == NULL) { // LCOV_EXCL_START
         // non-destructively remove the key again
-        kv_list->map_methods->remove(&kv_list->map->map_base.base, key, &map_data);
+        void *dummy;
+        kv_list->map_methods->remove(&kv_list->map->map_base.base, key, &dummy);
         return 1;
     } // LCOV_EXCL_STOP
-    *map_data = node_data;
+    *(void**)map_entry.value = node_data;
 
     // write the key to the node
     CxHashKey *loc_key = cx_kv_list_loc_key(kv_list, node_data);
-    *loc_key = key;
+    *loc_key = *map_entry.key;
 
     return 0;
 }
--- a/ucx/linked_list.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/linked_list.c	Fri Dec 19 17:53:18 2025 +0100
@@ -31,6 +31,15 @@
 #include <string.h>
 #include <assert.h>
 
+#if __STDC_VERSION__ < 202311L
+// we cannot simply include stdalign.h
+// because Solaris is not entirely C11 complaint
+#ifndef __alignof_is_defined
+#define alignof _Alignof
+#define __alignof_is_defined 1
+#endif
+#endif
+
 // LOW LEVEL LINKED LIST FUNCTIONS
 
 #define CX_LL_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))
@@ -56,13 +65,14 @@
     return (void *) cur;
 }
 
-void *cx_linked_list_find(
+void *cx_linked_list_find_c(
         const void *start,
         ptrdiff_t loc_advance,
         ptrdiff_t loc_data,
-        cx_compare_func cmp_func,
         const void *elem,
-        size_t *found_index
+        size_t *found_index,
+        cx_compare_func2 cmp_func,
+        void *context
 ) {
     assert(start != NULL);
     assert(loc_advance >= 0);
@@ -73,7 +83,7 @@
     size_t index = 0;
     do {
         void *current = ll_data(node);
-        if (cmp_func(current, elem) == 0) {
+        if (cmp_func(current, elem, context) == 0) {
             if (found_index != NULL) {
                 *found_index = index;
             }
@@ -85,6 +95,19 @@
     return NULL;
 }
 
+void *cx_linked_list_find(
+        const void *start,
+        ptrdiff_t loc_advance,
+        ptrdiff_t loc_data,
+        const void *elem,
+        size_t *found_index,
+        cx_compare_func cmp_func
+) {
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    return cx_linked_list_find_c(start, loc_advance, loc_data,
+        elem, found_index, cx_ccmp_wrap, &wrapper);
+}
+
 void *cx_linked_list_first(
         const void *node,
         ptrdiff_t loc_prev
@@ -231,26 +254,14 @@
     }
 }
 
-void cx_linked_list_insert_sorted(
-        void **begin,
-        void **end,
-        ptrdiff_t loc_prev,
-        ptrdiff_t loc_next,
-        void *new_node,
-        cx_compare_func cmp_func
-) {
-    assert(ll_next(new_node) == NULL);
-    cx_linked_list_insert_sorted_chain(
-            begin, end, loc_prev, loc_next, new_node, cmp_func);
-}
-
 static void *cx_linked_list_insert_sorted_chain_impl(
         void **begin,
         void **end,
         ptrdiff_t loc_prev,
         ptrdiff_t loc_next,
         void *insert_begin,
-        cx_compare_func cmp_func,
+        cx_compare_func2 cmp_func,
+        void *context,
         bool allow_duplicates
 ) {
     assert(begin != NULL);
@@ -267,7 +278,7 @@
 
     // determine the new start
     {
-        int d = source_original ==  NULL ? 1 : cmp_func(source_original, source_argument);
+        int d = source_original ==  NULL ? 1 : cmp_func(source_original, source_argument, context);
         if (d <= 0) {
             // the new chain starts with the original chain
             new_begin = new_end = source_original;
@@ -293,7 +304,7 @@
 
     // now successively compare the elements and add them to the correct chains
     while (source_original != NULL && source_argument != NULL) {
-        int d = cmp_func(source_original, source_argument);
+        int d = cmp_func(source_original, source_argument, context);
         if (d <= 0) {
             // the original is not larger, add it to the chain
             cx_linked_list_link(new_end, source_original, loc_prev, loc_next);
@@ -318,7 +329,7 @@
         } else {
             // the original is larger, append the source argument to the chain
             // check if we must discard the source argument as duplicate
-            if (!allow_duplicates && cmp_func(new_end, source_argument) == 0) {
+            if (!allow_duplicates && cmp_func(new_end, source_argument, context) == 0) {
                 if (dup_end == NULL) {
                     dup_begin = dup_end = source_argument;
                 } else {
@@ -347,7 +358,7 @@
         } else {
             // otherwise we must check one-by-one
             while (source_argument != NULL) {
-                if (cmp_func(new_end, source_argument) == 0) {
+                if (cmp_func(new_end, source_argument, context) == 0) {
                     if (dup_end == NULL) {
                         dup_begin = dup_end = source_argument;
                     } else {
@@ -385,6 +396,19 @@
     return dup_begin;
 }
 
+void cx_linked_list_insert_sorted(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *new_node,
+        cx_compare_func cmp_func
+) {
+    assert(ll_next(new_node) == NULL);
+    cx_linked_list_insert_sorted_chain(
+            begin, end, loc_prev, loc_next, new_node, cmp_func);
+}
+
 void cx_linked_list_insert_sorted_chain(
         void **begin,
         void **end,
@@ -393,9 +417,10 @@
         void *insert_begin,
         cx_compare_func cmp_func
 ) {
+    cx_compare_func_wrapper wrapper = {cmp_func};
     cx_linked_list_insert_sorted_chain_impl(
             begin, end, loc_prev, loc_next,
-            insert_begin, cmp_func, true);
+            insert_begin, cx_ccmp_wrap, &wrapper, true);
 }
 
 int cx_linked_list_insert_unique(
@@ -419,9 +444,66 @@
         void *insert_begin,
         cx_compare_func cmp_func
 ) {
+    cx_compare_func_wrapper wrapper = {cmp_func};
     return cx_linked_list_insert_sorted_chain_impl(
             begin, end, loc_prev, loc_next,
-            insert_begin, cmp_func, false);
+            insert_begin, cx_ccmp_wrap, &wrapper, false);
+}
+
+void cx_linked_list_insert_sorted_c(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *new_node,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    assert(ll_next(new_node) == NULL);
+    cx_linked_list_insert_sorted_chain_c(
+            begin, end, loc_prev, loc_next, new_node, cmp_func, context);
+}
+
+void cx_linked_list_insert_sorted_chain_c(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *insert_begin,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    cx_linked_list_insert_sorted_chain_impl(
+            begin, end, loc_prev, loc_next,
+            insert_begin, cmp_func, context, true);
+}
+
+int cx_linked_list_insert_unique_c(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *new_node,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    assert(ll_next(new_node) == NULL);
+    return NULL != cx_linked_list_insert_unique_chain_c(
+            begin, end, loc_prev, loc_next, new_node, cmp_func, context);
+}
+
+void *cx_linked_list_insert_unique_chain_c(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *insert_begin,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    return cx_linked_list_insert_sorted_chain_impl(
+            begin, end, loc_prev, loc_next,
+            insert_begin, cmp_func, context, false);
 }
 
 size_t cx_linked_list_remove_chain(
@@ -502,6 +584,8 @@
 #endif
 
 static void cx_linked_list_sort_merge(
+        void **begin,
+        void **end,
         ptrdiff_t loc_prev,
         ptrdiff_t loc_next,
         ptrdiff_t loc_data,
@@ -509,21 +593,20 @@
         void *ls,
         void *le,
         void *re,
-        cx_compare_func cmp_func,
-        void **begin,
-        void **end
+        cx_compare_func2 cmp_func,
+        void *context
 ) {
     void *sbo[CX_LINKED_LIST_SORT_SBO_SIZE];
     void **sorted = length >= CX_LINKED_LIST_SORT_SBO_SIZE ?
                     cxMallocDefault(sizeof(void *) * length) : sbo;
-    if (sorted == NULL) abort();
+    if (sorted == NULL) abort(); // LCOV_EXCL_LINE
     void *rc, *lc;
 
     lc = ls;
     rc = le;
     size_t n = 0;
     while (lc && lc != le && rc != re) {
-        if (cmp_func(ll_data(lc), ll_data(rc)) <= 0) {
+        if (cmp_func(ll_data(lc), ll_data(rc), context) <= 0) {
             sorted[n] = lc;
             lc = ll_next(lc);
         } else {
@@ -557,13 +640,14 @@
     }
 }
 
-void cx_linked_list_sort( // NOLINT(misc-no-recursion) - purposely recursive function
+void cx_linked_list_sort_c( // NOLINT(misc-no-recursion) - purposely recursive function
         void **begin,
         void **end,
         ptrdiff_t loc_prev,
         ptrdiff_t loc_next,
         ptrdiff_t loc_data,
-        cx_compare_func cmp_func
+        cx_compare_func2 cmp_func,
+        void *context
 ) {
     assert(begin != NULL);
     assert(loc_next >= 0);
@@ -581,7 +665,7 @@
     // check how many elements are already sorted
     lc = ls;
     size_t ln = 1;
-    while (ll_next(lc) != NULL && cmp_func(ll_data(ll_next(lc)), ll_data(lc)) > 0) {
+    while (ll_next(lc) != NULL && cmp_func(ll_data(ll_next(lc)), ll_data(lc), context) > 0) {
         lc = ll_next(lc);
         ln++;
     }
@@ -593,7 +677,7 @@
         size_t rn = 1;
         rc = le;
         // skip already sorted elements
-        while (ll_next(rc) != NULL && cmp_func(ll_data(ll_next(rc)), ll_data(rc)) > 0) {
+        while (ll_next(rc) != NULL && cmp_func(ll_data(ll_next(rc)), ll_data(rc), context) > 0) {
             rc = ll_next(rc);
             rn++;
         }
@@ -601,27 +685,65 @@
 
         // {ls,...,le->prev} and {rs,...,re->prev} are sorted - merge them
         void *sorted_begin, *sorted_end;
-        cx_linked_list_sort_merge(loc_prev, loc_next, loc_data,
+        cx_linked_list_sort_merge(&sorted_begin, &sorted_end,
+                                  loc_prev, loc_next, loc_data,
                                   ln + rn, ls, le, re, cmp_func,
-                                  &sorted_begin, &sorted_end);
+                                  context);
 
         // Something left? Sort it!
         size_t remainder_length = cx_linked_list_size(re, loc_next);
         if (remainder_length > 0) {
             void *remainder = re;
-            cx_linked_list_sort(&remainder, NULL, loc_prev, loc_next, loc_data, cmp_func);
+            cx_linked_list_sort_c(&remainder, NULL, loc_prev, loc_next, loc_data, cmp_func, context);
 
             // merge sorted list with (also sorted) remainder
-            cx_linked_list_sort_merge(loc_prev, loc_next, loc_data,
+            cx_linked_list_sort_merge(&sorted_begin, &sorted_end,
+                                      loc_prev, loc_next, loc_data,
                                       ln + rn + remainder_length,
                                       sorted_begin, remainder, NULL, cmp_func,
-                                      &sorted_begin, &sorted_end);
+                                      context);
         }
         *begin = sorted_begin;
         if (end) *end = sorted_end;
     }
 }
 
+void cx_linked_list_sort(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        ptrdiff_t loc_data,
+        cx_compare_func cmp_func
+) {
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    cx_linked_list_sort_c(begin, end, loc_prev, loc_next, loc_data, cx_ccmp_wrap, &wrapper);
+}
+
+int cx_linked_list_compare_c(
+        const void *begin_left,
+        const void *begin_right,
+        ptrdiff_t loc_advance,
+        ptrdiff_t loc_data,
+        cx_compare_func2 cmp_func,
+        void *context
+) {
+    const void *left = begin_left, *right = begin_right;
+
+    while (left != NULL && right != NULL) {
+        const void *left_data = ll_data(left);
+        const void *right_data = ll_data(right);
+        int result = cmp_func(left_data, right_data, context);
+        if (result != 0) return result;
+        left = ll_advance(left);
+        right = ll_advance(right);
+    }
+
+    if (left != NULL) { return 1; }
+    else if (right != NULL) { return -1; }
+    else { return 0; }
+}
+
 int cx_linked_list_compare(
         const void *begin_left,
         const void *begin_right,
@@ -629,20 +751,9 @@
         ptrdiff_t loc_data,
         cx_compare_func cmp_func
 ) {
-    const void *left = begin_left, *right = begin_right;
-
-    while (left != NULL && right != NULL) {
-        const void *left_data = ll_data(left);
-        const void *right_data = ll_data(right);
-        int result = cmp_func(left_data, right_data);
-        if (result != 0) return result;
-        left = ll_advance(left);
-        right = ll_advance(right);
-    }
-
-    if (left != NULL) { return 1; }
-    else if (right != NULL) { return -1; }
-    else { return 0; }
+    cx_compare_func_wrapper wrapper = {cmp_func};
+    return cx_linked_list_compare_c(begin_left, begin_right,
+            loc_advance, loc_data, cx_ccmp_wrap, &wrapper);
 }
 
 void cx_linked_list_reverse(
@@ -692,8 +803,13 @@
 }
 
 static void *cx_ll_malloc_node(const cx_linked_list *list) {
-    return cxZalloc(list->base.collection.allocator,
-                    list->loc_data + list->base.collection.elem_size + list->extra_data_len);
+    size_t n;
+    if (list->extra_data_len == 0) {
+        n = list->loc_data + list->base.collection.elem_size;
+    } else {
+        n = list->loc_extra + list->extra_data_len;
+    }
+    return cxZalloc(list->base.collection.allocator, n);
 }
 
 static int cx_ll_insert_at(
@@ -784,13 +900,11 @@
     }
 }
 
-static _Thread_local cx_compare_func cx_ll_insert_sorted_cmp_func;
-static _Thread_local off_t cx_ll_insert_sorted_loc_data;
-
-static int cx_ll_insert_sorted_cmp_helper(const void *l, const void *r) {
-    const char *left = (const char*)l + cx_ll_insert_sorted_loc_data;
-    const char *right = (const char*)r + cx_ll_insert_sorted_loc_data;
-    return cx_ll_insert_sorted_cmp_func(left, right);
+static int cx_ll_insert_sorted_cmp_helper(const void *l, const void *r, void *c) {
+    cx_linked_list *list = c;
+    const char *left = (const char*)l + list->loc_data;
+    const char *right = (const char*)r + list->loc_data;
+    return cx_list_compare_wrapper(left, right, list);
 }
 
 static size_t cx_ll_insert_sorted_impl(
@@ -825,29 +939,19 @@
     }
     CX_LL_PTR(prev, ll->loc_next) = NULL;
 
-    // invoke the low level function
-    cx_ll_insert_sorted_cmp_func = list->collection.cmpfunc;
-    cx_ll_insert_sorted_loc_data = ll->loc_data;
-    if (allow_duplicates) {
-        cx_linked_list_insert_sorted_chain(
-                &ll->begin,
-                &ll->end,
-                ll->loc_prev,
-                ll->loc_next,
-                chain,
-                cx_ll_insert_sorted_cmp_helper
-        );
-        list->collection.size += inserted;
-    } else {
-        void *duplicates = cx_linked_list_insert_unique_chain(
-                &ll->begin,
-                &ll->end,
-                ll->loc_prev,
-                ll->loc_next,
-                chain,
-                cx_ll_insert_sorted_cmp_helper
-        );
-        list->collection.size += inserted;
+    // invoke the low-level function
+    void *duplicates = cx_linked_list_insert_sorted_chain_impl(
+            &ll->begin,
+            &ll->end,
+            ll->loc_prev,
+            ll->loc_next,
+            chain,
+            cx_ll_insert_sorted_cmp_helper,
+            list,
+            allow_duplicates
+    );
+    list->collection.size += inserted;
+    if (!allow_duplicates) {
         // free the nodes that did not make it into the list
         while (duplicates != NULL) {
             void *next = CX_LL_PTR(duplicates, ll->loc_next);
@@ -1076,12 +1180,12 @@
 
     size_t index;
     cx_linked_list *ll = (cx_linked_list *) list;
-    char *node = cx_linked_list_find(
+    char *node = cx_linked_list_find_c(
             ll->begin,
             ll->loc_next, ll->loc_data,
-            list->collection.cmpfunc, elem,
-            &index
-    );
+            elem, &index,
+            cx_list_compare_wrapper,
+            list);
     if (node == NULL) {
         return list->collection.size;
     }
@@ -1097,9 +1201,9 @@
 
 static void cx_ll_sort(struct cx_list_s *list) {
     cx_linked_list *ll = (cx_linked_list *) list;
-    cx_linked_list_sort(&ll->begin, &ll->end,
+    cx_linked_list_sort_c(&ll->begin, &ll->end,
                         ll->loc_prev, ll->loc_next, ll->loc_data,
-                        list->collection.cmpfunc);
+                        cx_list_compare_wrapper, list);
 }
 
 static void cx_ll_reverse(struct cx_list_s *list) {
@@ -1115,9 +1219,9 @@
     cx_linked_list *right = (cx_linked_list *) other;
     assert(left->loc_next == right->loc_next);
     assert(left->loc_data == right->loc_data);
-    return cx_linked_list_compare(left->begin, right->begin,
+    return cx_linked_list_compare_c(left->begin, right->begin,
                                   left->loc_next, left->loc_data,
-                                  list->collection.cmpfunc);
+                                  cx_list_compare_wrapper, (void*)list);
 }
 
 static bool cx_ll_iter_valid(const void *it) {
@@ -1215,7 +1319,7 @@
         return result;
     } else {
         if (cx_ll_insert_element(list, list->collection.size, elem) == NULL) {
-            return 1;
+            return 1; // LCOV_EXCL_LINE
         }
         iter->elem_count++;
         iter->index = list->collection.size;
@@ -1252,12 +1356,12 @@
         cx_ll_sort,
         cx_ll_compare,
         cx_ll_reverse,
+        NULL, // no overallocation supported
         cx_ll_iterator,
 };
 
 CxList *cxLinkedListCreate(
         const CxAllocator *allocator,
-        cx_compare_func comparator,
         size_t elem_size
 ) {
     if (allocator == NULL) {
@@ -1266,12 +1370,22 @@
 
     cx_linked_list *list = cxCalloc(allocator, 1, sizeof(cx_linked_list));
     if (list == NULL) return NULL;
-    list->extra_data_len = 0;
     list->loc_prev = 0;
     list->loc_next = sizeof(void*);
     list->loc_data = sizeof(void*)*2;
+    list->loc_extra = -1;
+    list->extra_data_len = 0;
     cx_list_init((CxList*)list, &cx_linked_list_class,
-            allocator, comparator, elem_size);
+            allocator, elem_size);
 
     return (CxList *) list;
 }
+
+void cx_linked_list_extra_data(cx_linked_list *list, size_t len) {
+    list->extra_data_len = len;
+
+    off_t loc_extra = list->loc_data + list->base.collection.elem_size;
+    size_t alignment = alignof(void*);
+    size_t padding = alignment - (loc_extra % alignment);
+    list->loc_extra = loc_extra + padding;
+}
--- a/ucx/list.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/list.c	Fri Dec 19 17:53:18 2025 +0100
@@ -31,189 +31,35 @@
 #include <string.h>
 #include <assert.h>
 
-// <editor-fold desc="Store Pointers Functionality">
-
-static _Thread_local cx_compare_func cx_pl_cmpfunc_impl;
+// we don't want to include the full array_list.h.
+// therefore, we only forward declare the one function we want to use
+CX_EXPORT void cx_array_qsort_c(void *array, size_t nmemb, size_t size,
+        cx_compare_func2 fn, void *context);
 
-static int cx_pl_cmpfunc(
-        const void *l,
-        const void *r
-) {
-    // l and r are guaranteed to be non-NULL pointing to the list's memory
-    void *const *lptr = l;
-    void *const *rptr = r;
-    const void *left = *lptr;
-    const void *right = *rptr;
-    if (left == NULL) {
-        // NULL is smaller than any value except NULL
-        return right == NULL ? 0 : -1;
-    } else if (right == NULL) {
-        // any value is larger than NULL
-        return 1;
-    }
-    return cx_pl_cmpfunc_impl(left, right);
-}
-
-static void cx_pl_hack_cmpfunc(const struct cx_list_s *list) {
-    // cast away const - this is the hacky thing
-    struct cx_collection_s *l = (struct cx_collection_s*) &list->collection;
-    cx_pl_cmpfunc_impl = l->cmpfunc;
-    l->cmpfunc = cx_pl_cmpfunc;
-}
-
-static void cx_pl_unhack_cmpfunc(const struct cx_list_s *list) {
-    // cast away const - this is the hacky thing
-    struct cx_collection_s *l = (struct cx_collection_s*) &list->collection;
-    l->cmpfunc = cx_pl_cmpfunc_impl;
-}
-
-static void cx_pl_destructor(struct cx_list_s *list) {
-    list->climpl->deallocate(list);
-}
 
-static void *cx_pl_insert_element(
-        struct cx_list_s *list,
-        size_t index,
-        const void *element
-) {
-    return list->climpl->insert_element(list, index, &element);
-}
-
-static size_t cx_pl_insert_array(
-        struct cx_list_s *list,
-        size_t index,
-        const void *array,
-        size_t n
-) {
-    return list->climpl->insert_array(list, index, array, n);
-}
-
-static size_t cx_pl_insert_sorted(
-        struct cx_list_s *list,
-        const void *array,
-        size_t n
-) {
-    cx_pl_hack_cmpfunc(list);
-    size_t result = list->climpl->insert_sorted(list, array, n);
-    cx_pl_unhack_cmpfunc(list);
-    return result;
-}
-
-static size_t cx_pl_insert_unique(
-        struct cx_list_s *list,
-        const void *array,
-        size_t n
-) {
-    cx_pl_hack_cmpfunc(list);
-    size_t result = list->climpl->insert_unique(list, array, n);
-    cx_pl_unhack_cmpfunc(list);
-    return result;
-}
-
-static int cx_pl_insert_iter(
-        struct cx_iterator_s *iter,
-        const void *elem,
-        int prepend
-) {
-    struct cx_list_s *list = iter->src_handle;
-    return list->climpl->insert_iter(iter, &elem, prepend);
+int cx_list_compare_wrapper(const void *l, const void *r, void *c) {
+    CxList *list = c;
+    const void *left;
+    const void *right;
+    if (cxCollectionStoresPointers(list)) {
+        left = *(void**)l;
+        right = *(void**)r;
+        // for historic reasons, we are handling the NULL case here
+        // because every UCX compare function does not support NULL arguments
+        if (left == NULL) {
+            if (right == NULL) return 0;
+            return -1;
+        } else if (right == NULL) {
+            return 1;
+        }
+    } else {
+        left = l;
+        right = r;
+    }
+    return cx_invoke_compare_func(list, left, right);
 }
 
-static size_t cx_pl_remove(
-        struct cx_list_s *list,
-        size_t index,
-        size_t num,
-        void *targetbuf
-) {
-    return list->climpl->remove(list, index, num, targetbuf);
-}
-
-static void cx_pl_clear(struct cx_list_s *list) {
-    list->climpl->clear(list);
-}
-
-static int cx_pl_swap(
-        struct cx_list_s *list,
-        size_t i,
-        size_t j
-) {
-    return list->climpl->swap(list, i, j);
-}
-
-static void *cx_pl_at(
-        const struct cx_list_s *list,
-        size_t index
-) {
-    void **ptr = list->climpl->at(list, index);
-    return ptr == NULL ? NULL : *ptr;
-}
-
-static size_t cx_pl_find_remove(
-        struct cx_list_s *list,
-        const void *elem,
-        bool remove
-) {
-    cx_pl_hack_cmpfunc(list);
-    size_t ret = list->climpl->find_remove(list, &elem, remove);
-    cx_pl_unhack_cmpfunc(list);
-    return ret;
-}
-
-static void cx_pl_sort(struct cx_list_s *list) {
-    cx_pl_hack_cmpfunc(list);
-    list->climpl->sort(list);
-    cx_pl_unhack_cmpfunc(list);
-}
-
-static int cx_pl_compare(
-        const struct cx_list_s *list,
-        const struct cx_list_s *other
-) {
-    cx_pl_hack_cmpfunc(list);
-    int ret = list->climpl->compare(list, other);
-    cx_pl_unhack_cmpfunc(list);
-    return ret;
-}
-
-static void cx_pl_reverse(struct cx_list_s *list) {
-    list->climpl->reverse(list);
-}
-
-static void *cx_pl_iter_current(const void *it) {
-    const struct cx_iterator_s *iter = it;
-    void **ptr = iter->base.current_impl(it);
-    return ptr == NULL ? NULL : *ptr;
-}
-
-static struct cx_iterator_s cx_pl_iterator(
-        const struct cx_list_s *list,
-        size_t index,
-        bool backwards
-) {
-    struct cx_iterator_s iter = list->climpl->iterator(list, index, backwards);
-    iter.base.current_impl = iter.base.current;
-    iter.base.current = cx_pl_iter_current;
-    return iter;
-}
-
-static cx_list_class cx_pointer_list_class = {
-        cx_pl_destructor,
-        cx_pl_insert_element,
-        cx_pl_insert_array,
-        cx_pl_insert_sorted,
-        cx_pl_insert_unique,
-        cx_pl_insert_iter,
-        cx_pl_remove,
-        cx_pl_clear,
-        cx_pl_swap,
-        cx_pl_at,
-        cx_pl_find_remove,
-        cx_pl_sort,
-        cx_pl_compare,
-        cx_pl_reverse,
-        cx_pl_iterator,
-};
-// </editor-fold>
+#define cx_list_compare_wrapper(l, r, c) cx_list_compare_wrapper(l, r, (void*)c)
 
 // <editor-fold desc="empty list implementation">
 
@@ -267,33 +113,31 @@
         cx_emptyl_noop,
         NULL,
         cx_emptyl_noop,
+        NULL,
         cx_emptyl_iterator,
 };
 
 CxList cx_empty_list = {
     {
         NULL,
-        NULL,
         0,
         0,
         NULL,
         NULL,
         NULL,
+        NULL,
+        NULL,
+        NULL,
         false,
         true,
     },
     &cx_empty_list_class,
-    NULL
 };
 
 CxList *const cxEmptyList = &cx_empty_list;
 
 // </editor-fold>
 
-#define invoke_list_func(name, list, ...) \
-    ((list)->climpl == NULL ? (list)->cl->name : (list)->climpl->name) \
-    (list, __VA_ARGS__)
-
 size_t cx_list_default_insert_array(
         struct cx_list_s *list,
         size_t index,
@@ -303,8 +147,7 @@
     const char *src = data;
     size_t i = 0;
     for (; i < n; i++) {
-        if (NULL == invoke_list_func(
-            insert_element, list, index + i, src)
+        if (NULL == list->cl->insert_element(list, index + i, src)
         ) {
             return i; // LCOV_EXCL_LINE
         }
@@ -325,7 +168,6 @@
     if (n == 0) return 0;
 
     size_t elem_size = list->collection.elem_size;
-    cx_compare_func cmp = list->collection.cmpfunc;
     const char *src = sorted_data;
 
     // track indices and number of inserted items
@@ -333,19 +175,19 @@
 
     // search the list for insertion points
     while (di < list->collection.size) {
-        const void *list_elm = invoke_list_func(at, list, di);
+        const void *list_elm = list->cl->at(list, di);
 
         // compare the current list element with the first source element
         // if less, skip the list elements
         // if equal, skip the list elements and optionally the source elements
         {
-            int d = cmp(list_elm, src);
+            int d = cx_list_compare_wrapper(list_elm, src, list);
             if (d <= 0) {
                 if (!allow_duplicates && d == 0) {
                     src += elem_size;
                     si++;
                     processed++; // we also count duplicates for the return value
-                    while (si < n && cmp(list_elm, src) == 0) {
+                    while (si < n && cx_list_compare_wrapper(list_elm, src, list) == 0) {
                         src += elem_size;
                         si++;
                         processed++;
@@ -365,7 +207,7 @@
         while (++si < n) {
             if (!allow_duplicates) {
                 // skip duplicates within the source
-                if (cmp(next, next + elem_size) == 0) {
+                if (cx_list_compare_wrapper(next, next + elem_size, list) == 0) {
                     next += elem_size;
                     skip++;
                     continue;
@@ -379,7 +221,7 @@
             }
             next += elem_size;
             // once we become larger than the list elem, break
-            if (cmp(list_elm, next) <= 0) {
+            if (cx_list_compare_wrapper(list_elm, next, list) <= 0) {
                 break;
             }
             // otherwise, we can insert one more
@@ -388,11 +230,11 @@
 
         // insert the elements at location si
         if (ins == 1) {
-            if (NULL == invoke_list_func(insert_element, list, di, src)) {
+            if (NULL == list->cl->insert_element(list, di, src)) {
                 return processed; // LCOV_EXCL_LINE
             }
         } else {
-            size_t r = invoke_list_func(insert_array, list, di, src, ins);
+            size_t r = list->cl->insert_array(list, di, src, ins);
             if (r < ins) {
                 return processed + r;  // LCOV_EXCL_LINE
             }
@@ -410,13 +252,13 @@
     // insert remaining items
     if (si < n) {
         if (allow_duplicates) {
-            processed += invoke_list_func(insert_array, list, di, src, n - si);
+            processed += list->cl->insert_array(list, di, src, n - si);
         } else {
-            const void *last = di == 0 ? NULL : invoke_list_func(at, list, di - 1);
+            const void *last = di == 0 ? NULL : list->cl->at(list, di - 1);
             for (; si < n; si++) {
                 // skip duplicates within the source
-                if (last == NULL || cmp(last, src) != 0) {
-                    if (NULL == invoke_list_func(insert_element, list, di, src)) {
+                if (last == NULL || cx_list_compare_wrapper(last, src, list) != 0) {
+                    if (NULL == list->cl->insert_element(list, di, src)) {
                         return processed; // LCOV_EXCL_LINE
                     }
                     last = src;
@@ -456,19 +298,18 @@
     // copy elements from source array
     char *loc = tmp;
     for (size_t i = 0; i < list_size; i++) {
-        void *src = invoke_list_func(at, list, i);
+        void *src = list->cl->at(list, i);
         memcpy(loc, src, elem_size);
         loc += elem_size;
     }
 
     // qsort
-    qsort(tmp, list_size, elem_size,
-          list->collection.cmpfunc);
+    cx_array_qsort_c(tmp, list_size, elem_size, cx_list_compare_wrapper, list);
 
     // copy elements back
     loc = tmp;
     for (size_t i = 0; i < list_size; i++) {
-        void *dest = invoke_list_func(at, list, i);
+        void *dest = list->cl->at(list, i);
         memcpy(dest, loc, elem_size);
         loc += elem_size;
     }
@@ -486,8 +327,8 @@
     void *tmp = cxMallocDefault(elem_size);
     if (tmp == NULL) return 1; // LCOV_EXCL_LINE
 
-    void *ip = invoke_list_func(at, list, i);
-    void *jp = invoke_list_func(at, list, j);
+    void *ip = list->cl->at(list, i);
+    void *jp = list->cl->at(list, j);
 
     memcpy(tmp, ip, elem_size);
     memcpy(ip, jp, elem_size);
@@ -502,22 +343,24 @@
     struct cx_list_s *list,
     struct cx_list_class_s *cl,
     const struct cx_allocator_s *allocator,
-    cx_compare_func comparator,
     size_t elem_size
 ) {
     list->cl = cl;
     list->collection.allocator = allocator;
-    list->collection.cmpfunc = comparator;
+    list->collection.size = 0;
+    list->collection.sorted = false; // should be set by the implementation
     if (elem_size > 0) {
         list->collection.elem_size = elem_size;
+        list->collection.simple_cmp = NULL;
+        list->collection.advanced_cmp = cx_ccmp_memcmp;
+        list->collection.cmp_data = &list->collection.elem_size;
+        list->collection.store_pointer = false;
     } else {
         list->collection.elem_size = sizeof(void *);
-        if (list->collection.cmpfunc == NULL) {
-            list->collection.cmpfunc = cx_cmp_ptr;
-        }
+        list->collection.simple_cmp = cx_cmp_ptr;
+        list->collection.advanced_cmp = NULL;
+        list->collection.cmp_data = NULL;
         list->collection.store_pointer = true;
-        list->climpl = list->cl;
-        list->cl = &cx_pointer_list_class;
     }
 }
 
@@ -525,33 +368,28 @@
         const CxList *list,
         const CxList *other
 ) {
+    // check if we cannot use the list internal function
     bool cannot_optimize = false;
 
     // if one is storing pointers but the other is not
     cannot_optimize |= list->collection.store_pointer ^ other->collection.store_pointer;
 
-    // if one class is wrapped but the other is not
-    cannot_optimize |= (list->climpl == NULL) ^ (other->climpl == NULL);
-
-    // if the compare functions do not match or both are NULL
-    if (!cannot_optimize) {
-        cx_compare_func list_cmp = (cx_compare_func) (list->climpl != NULL ?
-                                                      list->climpl->compare : list->cl->compare);
-        cx_compare_func other_cmp = (cx_compare_func) (other->climpl != NULL ?
-                                                       other->climpl->compare : other->cl->compare);
-        cannot_optimize |= list_cmp != other_cmp;
-        cannot_optimize |= list_cmp == NULL;
-    }
+    // check if the lists are incompatible or this list does not implement compare
+    cx_compare_func list_cmp = (cx_compare_func) list->cl->compare;
+    cx_compare_func other_cmp = (cx_compare_func) other->cl->compare;
+    cannot_optimize |= list_cmp != other_cmp;
+    cannot_optimize |= list_cmp == NULL;
 
     if (cannot_optimize) {
         // lists are definitely different - cannot use internal compare function
         if (list->collection.size == other->collection.size) {
-            CxIterator left = list->cl->iterator(list, 0, false);
-            CxIterator right = other->cl->iterator(other, 0, false);
+            CxIterator left = cxListIterator(list);
+            CxIterator right = cxListIterator(other);
             for (size_t i = 0; i < list->collection.size; i++) {
                 void *leftValue = cxIteratorCurrent(left);
                 void *rightValue = cxIteratorCurrent(right);
-                int d = list->collection.cmpfunc(leftValue, rightValue);
+                // values are already unwrapped, invoke immediately
+                int d = cx_invoke_compare_func(list, leftValue, rightValue);
                 if (d != 0) {
                     return d;
                 }
@@ -574,7 +412,7 @@
 
 int cxListAdd(CxList *list, const void *elem) {
     list->collection.sorted = false;
-    return list->cl->insert_element(list, list->collection.size, elem) == NULL;
+    return list->cl->insert_element(list, list->collection.size, cx_ref(list, elem)) == NULL;
 }
 
 size_t cxListAddArray(CxList *list, const void *array, size_t n) {
@@ -584,7 +422,7 @@
 
 int cxListInsert(CxList *list, size_t index, const void *elem) {
     list->collection.sorted = false;
-    return list->cl->insert_element(list, index, elem) == NULL;
+    return list->cl->insert_element(list, index, cx_ref(list, elem)) == NULL;
 }
 
 void *cxListEmplaceAt(CxList *list, size_t index) {
@@ -611,11 +449,6 @@
     iter.index = 0;
     // replace the valid function to abort iteration when c is reached
     iter.base.valid = cx_list_emplace_iterator_valid;
-    // if we are storing pointers, we want to return the pure pointers.
-    // therefore, we must unwrap the "current" method
-    if (list->collection.store_pointer) {
-        iter.base.current = iter.base.current_impl;
-    }
     return iter;
 }
 
@@ -626,15 +459,13 @@
 int cxListInsertSorted(CxList *list, const void *elem) {
     assert(cxCollectionSorted(list));
     list->collection.sorted = true;
-    const void *data = list->collection.store_pointer ? &elem : elem;
-    return list->cl->insert_sorted(list, data, 1) == 0;
+    return list->cl->insert_sorted(list, cx_ref(list, elem), 1) == 0;
 }
 
 int cxListInsertUnique(CxList *list, const void *elem) {
     if (cxCollectionSorted(list)) {
         list->collection.sorted = true;
-        const void *data = list->collection.store_pointer ? &elem : elem;
-        return list->cl->insert_unique(list, data, 1) == 0;
+        return list->cl->insert_unique(list, cx_ref(list, elem), 1) == 0;
     } else {
         if (cxListContains(list, elem)) {
             return 0;
@@ -663,8 +494,7 @@
         const char *source = array;
         for (size_t i = 0 ; i < n; i++) {
             // note: this also checks elements added in a previous iteration
-            const void *data = list->collection.store_pointer ?
-                    *((const void**)source) : source;
+            const void *data = cx_deref(list, source);
             if (!cxListContains(list, data)) {
                 if (cxListAdd(list, data)) {
                     return i; // LCOV_EXCL_LINE
@@ -677,15 +507,15 @@
 }
 
 int cxListInsertAfter(CxIterator *iter, const void *elem) {
-    CxList* list = (CxList*)iter->src_handle;
+    CxList* list = iter->src_handle;
     list->collection.sorted = false;
-    return list->cl->insert_iter(iter, elem, 0);
+    return list->cl->insert_iter(iter, cx_ref(list, elem), 0);
 }
 
 int cxListInsertBefore(CxIterator *iter, const void *elem) {
-    CxList* list = (CxList*)iter->src_handle;
+    CxList* list = iter->src_handle;
     list->collection.sorted = false;
-    return list->cl->insert_iter(iter, elem, 1);
+    return list->cl->insert_iter(iter, cx_ref(list, elem), 1);
 }
 
 int cxListRemove(CxList *list, size_t index) {
@@ -724,15 +554,17 @@
 }
 
 void *cxListAt(const CxList *list, size_t index) {
-    return list->cl->at(list, index);
+    void *result = list->cl->at(list, index);
+    if (result == NULL) return NULL;
+    return cx_deref(list, result);
 }
 
 void *cxListFirst(const CxList *list) {
-    return list->cl->at(list, 0);
+    return cxListAt(list, 0);
 }
 
 void *cxListLast(const CxList *list) {
-    return list->cl->at(list, list->collection.size - 1);
+    return cxListAt(list, list->collection.size - 1);
 }
 
 int cxListSet(CxList *list, size_t index, const void *elem) {
@@ -741,8 +573,7 @@
     }
 
     if (list->collection.store_pointer) {
-        // For pointer collections, always use climpl
-        void **target = list->climpl->at(list, index);
+        void **target = list->cl->at(list, index);
         *target = (void *)elem;
     } else {
         void *target = list->cl->at(list, index);
@@ -752,32 +583,48 @@
     return 0;
 }
 
+static void *cx_pl_iter_current(const void *it) {
+    const struct cx_iterator_s *iter = it;
+    void **ptr = iter->base.current_impl(it);
+    return ptr == NULL ? NULL : *ptr;
+}
+
+CX_INLINE CxIterator cx_pl_iter_wrap(const CxList *list, CxIterator iter) {
+    if (cxCollectionStoresPointers(list)) {
+        iter.base.current_impl = iter.base.current;
+        iter.base.current = cx_pl_iter_current;
+        return iter;
+    } else {
+        return iter;
+    }
+}
+
 CxIterator cxListIteratorAt(const CxList *list, size_t index) {
     if (list == NULL) list = cxEmptyList;
-    return list->cl->iterator(list, index, false);
+    return cx_pl_iter_wrap(list, list->cl->iterator(list, index, false));
 }
 
 CxIterator cxListBackwardsIteratorAt(const CxList *list, size_t index) {
     if (list == NULL) list = cxEmptyList;
-    return list->cl->iterator(list, index, true);
+    return cx_pl_iter_wrap(list, list->cl->iterator(list, index, true));
 }
 
 CxIterator cxListIterator(const CxList *list) {
     if (list == NULL) list = cxEmptyList;
-    return list->cl->iterator(list, 0, false);
+    return cx_pl_iter_wrap(list, list->cl->iterator(list, 0, false));
 }
 
 CxIterator cxListBackwardsIterator(const CxList *list) {
     if (list == NULL) list = cxEmptyList;
-    return list->cl->iterator(list, list->collection.size - 1, true);
+    return cx_pl_iter_wrap(list, list->cl->iterator(list, list->collection.size - 1, true));
 }
 
 size_t cxListFind(const CxList *list, const void *elem) {
-    return list->cl->find_remove((CxList*)list, elem, false);
+    return list->cl->find_remove((CxList*)list, cx_ref(list, elem), false);
 }
 
 bool cxListContains(const CxList* list, const void* elem) {
-    return list->cl->find_remove((CxList*)list, elem, false) < list->collection.size;
+    return list->cl->find_remove((CxList*)list, cx_ref(list, elem), false) < list->collection.size;
 }
 
 bool cxListIndexValid(const CxList *list, size_t index) {
@@ -785,7 +632,7 @@
 }
 
 size_t cxListFindRemove(CxList *list, const void *elem) {
-    return list->cl->find_remove(list, elem, true);
+    return list->cl->find_remove(list, cx_ref(list, elem), true);
 }
 
 void cxListSort(CxList *list) {
@@ -819,6 +666,15 @@
     list->collection.advanced_destructor = destr2_bak;
 }
 
+static void* cx_list_shallow_clone_func(void *dst, const void *src, const CxAllocator *al, void *data) {
+    size_t elem_size = *(size_t*)data;
+    if (dst == NULL) dst = cxMalloc(al, elem_size);
+    if (dst != NULL) memcpy(dst, src, elem_size);
+    return dst;
+}
+
+#define use_shallow_clone_func(list) cx_list_shallow_clone_func, NULL, (void*)&((list)->collection.elem_size)
+
 int cxListClone(CxList *dst, const CxList *src, cx_clone_func clone_func,
         const CxAllocator *clone_allocator, void *data) {
     if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
@@ -858,6 +714,11 @@
         return 1;
     }
 
+    // set the sorted flag when we know it's sorted
+    if (orig_size == 0 && src->collection.sorted) {
+        dst->collection.sorted = true;
+    }
+
     return 0;
 }
 
@@ -878,8 +739,7 @@
             int d;
             if (cxIteratorValid(sub_iter)) {
                 sub_elem = cxIteratorCurrent(sub_iter);
-                cx_compare_func cmp = subtrahend->collection.cmpfunc;
-                d = cmp(sub_elem, min_elem);
+                d = cx_list_compare_wrapper(sub_elem, min_elem, subtrahend);
             } else {
                 // no more elements in the subtrahend,
                 // i.e., the min_elem is larger than any elem of the subtrahend
@@ -947,7 +807,7 @@
         while (cxIteratorValid(src_iter) && cxIteratorValid(other_iter)) {
             void *src_elem = cxIteratorCurrent(src_iter);
             void *other_elem = cxIteratorCurrent(other_iter);
-            int d = src->collection.cmpfunc(src_elem, other_elem);
+            int d = cx_list_compare_wrapper(src_elem, other_elem, src);
             if (d == 0) {
                 // is contained, clone it
                 void **dst_mem = cxListEmplace(dst);
@@ -1006,7 +866,7 @@
         CxIterator src_iter = cxListIterator(src);
         CxIterator other_iter = cxListIterator(other);
         while (cxIteratorValid(src_iter) || cxIteratorValid(other_iter)) {
-            void *src_elem, *other_elem;
+            void *src_elem = NULL, *other_elem = NULL;
             int d;
             if (!cxIteratorValid(src_iter)) {
                 other_elem = cxIteratorCurrent(other_iter);
@@ -1017,39 +877,33 @@
             } else {
                 src_elem = cxIteratorCurrent(src_iter);
                 other_elem = cxIteratorCurrent(other_iter);
-                d = src->collection.cmpfunc(src_elem, other_elem);
+                d = cx_list_compare_wrapper(src_elem, other_elem, src);
             }
-            if (d <= 0) {
-                // source element is smaller or equal, clone it
-                void **dst_mem = cxListEmplace(dst);
-                void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
-                void* dst_ptr = clone_func(target, src_elem, clone_allocator, data);
-                if (dst_ptr == NULL) {
-                    cx_list_pop_uninitialized_elements(dst, 1);
-                    return 1;
-                }
-                if (cxCollectionStoresPointers(dst)) {
-                    *dst_mem = dst_ptr;
-                }
+            void *clone_from;
+            if (d < 0) {
+                // source element is smaller clone it
+                clone_from = src_elem;
                 cxIteratorNext(src_iter);
-                // if the other element was equal, skip it
-                if (d == 0) {
-                    cxIteratorNext(other_iter);
-                }
+            } else if (d == 0) {
+                // both elements are equal, clone from the source, skip other
+                clone_from = src_elem;
+                cxIteratorNext(src_iter);
+                cxIteratorNext(other_iter);
             } else {
                 // the other element is smaller, clone it
-                void **dst_mem = cxListEmplace(dst);
-                void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
-                void* dst_ptr = clone_func(target, other_elem, clone_allocator, data);
-                if (dst_ptr == NULL) {
-                    cx_list_pop_uninitialized_elements(dst, 1);
-                    return 1;
-                }
-                if (cxCollectionStoresPointers(dst)) {
-                    *dst_mem = dst_ptr;
-                }
+                clone_from = other_elem;
                 cxIteratorNext(other_iter);
             }
+            void **dst_mem = cxListEmplace(dst);
+            void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+            void* dst_ptr = clone_func(target, clone_from, clone_allocator, data);
+            if (dst_ptr == NULL) {
+                cx_list_pop_uninitialized_elements(dst, 1);
+                return 1;
+            }
+            if (cxCollectionStoresPointers(dst)) {
+                *dst_mem = dst_ptr;
+            }
         }
 
         // if dst was empty, it is now guaranteed to be sorted
@@ -1078,3 +932,36 @@
 
     return 0;
 }
+
+int cxListCloneShallow(CxList *dst, const CxList *src) {
+    return cxListClone(dst, src, use_shallow_clone_func(src));
+}
+
+int cxListDifferenceShallow(CxList *dst, const CxList *minuend, const CxList *subtrahend) {
+    return cxListDifference(dst, minuend, subtrahend, use_shallow_clone_func(minuend));
+}
+
+int cxListIntersectionShallow(CxList *dst, const CxList *src, const CxList *other) {
+    return cxListIntersection(dst, src, other, use_shallow_clone_func(src));
+}
+
+int cxListUnionShallow(CxList *dst, const CxList *src, const CxList *other) {
+    return cxListUnion(dst, src, other, use_shallow_clone_func(src));
+}
+
+int cxListReserve(CxList *list, size_t capacity) {
+    if (list->cl->change_capacity == NULL) {
+        return 0;
+    }
+    if (capacity <= cxCollectionSize(list)) {
+        return 0;
+    }
+    return list->cl->change_capacity(list, capacity);
+}
+
+int cxListShrink(CxList *list) {
+    if (list->cl->change_capacity == NULL) {
+        return 0;
+    }
+    return list->cl->change_capacity(list, cxCollectionSize(list));
+}
--- a/ucx/map.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/map.c	Fri Dec 19 17:53:18 2025 +0100
@@ -70,12 +70,14 @@
 CxMap cx_empty_map = {
     {
         NULL,
-        NULL,
         0,
         0,
         NULL,
         NULL,
         NULL,
+        NULL,
+        NULL,
+        NULL,
         false,
         true
     },
@@ -110,11 +112,13 @@
 }
 
 int cx_map_put(CxMap *map, CxHashKey key, void *value) {
-    return map->cl->put(map, key, value) == NULL;
+    return map->cl->put(map, key, value).key == NULL;
 }
 
 void *cx_map_emplace(CxMap *map, CxHashKey key) {
-    return map->cl->put(map, key, NULL);
+    const CxMapEntry entry = map->cl->put(map, key, NULL);
+    if (entry.key == NULL) return NULL;
+    return entry.value;
 }
 
 void *cx_map_get(const CxMap *map, CxHashKey key) {
@@ -140,6 +144,15 @@
     map->collection.advanced_destructor = destr2_bak;
 }
 
+static void* cx_map_shallow_clone_func(void *dst, const void *src, const CxAllocator *al, void *data) {
+    size_t elem_size = *(size_t*)data;
+    if (dst == NULL) dst = cxMalloc(al, elem_size);
+    if (dst != NULL) memcpy(dst, src, elem_size);
+    return dst;
+}
+
+#define use_shallow_clone_func(map) cx_map_shallow_clone_func, NULL, (void*)&((map)->collection.elem_size)
+
 int cxMapClone(CxMap *dst, const CxMap *src, cx_clone_func clone_func,
         const CxAllocator *clone_allocator, void *data) {
     if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
@@ -293,3 +306,56 @@
     }
     return 0;
 }
+
+int cxMapCloneShallow(CxMap *dst, const CxMap *src) {
+    return cxMapClone(dst, src, use_shallow_clone_func(src));
+}
+
+int cxMapDifferenceShallow(CxMap *dst, const CxMap *minuend, const CxMap *subtrahend) {
+    return cxMapDifference(dst, minuend, subtrahend, use_shallow_clone_func(minuend));
+}
+
+int cxMapListDifferenceShallow(CxMap *dst, const CxMap *src, const CxList *keys) {
+    return cxMapListDifference(dst, src, keys, use_shallow_clone_func(src));
+}
+
+int cxMapIntersectionShallow(CxMap *dst, const CxMap *src, const CxMap *other) {
+    return cxMapIntersection(dst, src, other, use_shallow_clone_func(src));
+}
+
+int cxMapListIntersectionShallow(CxMap *dst, const CxMap *src, const CxList *keys) {
+    return cxMapListIntersection(dst, src, keys, use_shallow_clone_func(src));
+}
+
+int cxMapUnionShallow(CxMap *dst, const CxMap *src) {
+    return cxMapUnion(dst, src, use_shallow_clone_func(src));
+}
+
+int cxMapCompare(const CxMap *map, const CxMap *other) {
+    // compare map sizes
+    const size_t size_left = cxMapSize(map);
+    const size_t size_right = cxMapSize(other);
+    if (size_left < size_right) {
+        return -1;
+    } else if (size_left > size_right) {
+        return 1;
+    }
+
+    // iterate through the first map
+    CxMapIterator iter = cxMapIterator(map);
+    cx_foreach(const CxMapEntry *, entry, iter) {
+        const void *value_left = entry->value;
+        const void *value_right = cxMapGet(other, *entry->key);
+        // if the other map does not have the key, we are done
+        if (value_right == NULL) {
+            return -1;
+        }
+        // compare the values
+        const int d = cx_invoke_compare_func(map, value_left, value_right);
+        if (d != 0) {
+            return d;
+        }
+    }
+
+    return 0;
+}
--- a/ucx/printf.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/printf.c	Fri Dec 19 17:53:18 2025 +0100
@@ -61,8 +61,10 @@
     va_copy(ap2, ap);
     int ret = vsnprintf(buf, CX_PRINTF_SBO_SIZE, fmt, ap);
     if (ret < 0) {
+        // LCOV_EXCL_START
         va_end(ap2);
         return ret;
+        // LCOV_EXCL_STOP
     } else if (ret < CX_PRINTF_SBO_SIZE) {
         va_end(ap2);
         return (int) wfc(buf, 1, ret, stream);
@@ -121,8 +123,10 @@
         if (s.ptr) {
             ret = vsnprintf(s.ptr, len, fmt, ap2);
             if (ret < 0) {
+                // LCOV_EXCL_START
                 cxFree(a, s.ptr);
                 s.ptr = NULL;
+                // LCOV_EXCL_STOP
             } else {
                 s.length = (size_t) ret;
             }
@@ -162,7 +166,7 @@
         if (ptr) {
             int newret = vsnprintf(ptr, newlen, fmt, ap2);
             if (newret < 0) {
-                cxFree(alloc, ptr);
+                cxFree(alloc, ptr); // LCOV_EXCL_LINE
             } else {
                 *len = newlen;
                 *str = ptr;
@@ -207,7 +211,7 @@
         if (ptr) {
             int newret = vsnprintf(ptr, newlen, fmt, ap2);
             if (newret < 0) {
-                cxFree(alloc, ptr);
+                cxFree(alloc, ptr); // LCOV_EXCL_LINE
             } else {
                 *len = newlen;
                 *str = ptr;
--- a/ucx/properties.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/properties.c	Fri Dec 19 17:53:18 2025 +0100
@@ -29,12 +29,15 @@
 #include "cx/properties.h"
 
 #include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
 
 const CxPropertiesConfig cx_properties_config_default = {
-        '=',
-        '#',
-        '\0',
-        '\0',
+    '=',
+    '#',
+    '\0',
+    '\0',
     '\\',
 };
 
@@ -65,8 +68,8 @@
     if (cxBufferEof(&prop->input)) {
         // destroy a possible previously initialized buffer
         cxBufferDestroy(&prop->input);
-        cxBufferInit(&prop->input, (void*) buf, len,
-            NULL, CX_BUFFER_COPY_ON_WRITE | CX_BUFFER_AUTO_EXTEND);
+        cxBufferInit(&prop->input, NULL, (void*) buf,
+                     len, CX_BUFFER_COPY_ON_WRITE | CX_BUFFER_AUTO_EXTEND);
         prop->input.size = len;
     } else {
         if (cxBufferAppend(buf, 1, len, &prop->input) < len) return -1;
@@ -79,7 +82,7 @@
         char *buf,
         size_t capacity
 ) {
-    cxBufferInit(&prop->buffer, buf, capacity, NULL, CX_BUFFER_COPY_ON_EXTEND);
+    cxBufferInit(&prop->buffer, NULL, buf, capacity, CX_BUFFER_COPY_ON_EXTEND);
 }
 
 CxPropertiesStatus cxPropertiesNext(
@@ -94,13 +97,30 @@
 
     // a pointer to the buffer we want to read from
     CxBuffer *current_buffer = &prop->input;
-
+    
+    char comment1 = prop->config.comment1;
+    char comment2 = prop->config.comment2;
+    char comment3 = prop->config.comment3;
+    char delimiter = prop->config.delimiter;
+    char continuation = prop->config.continuation;
+    
     // check if we have rescued data
     if (!cxBufferEof(&prop->buffer)) {
         // check if we can now get a complete line
         cxstring input = cx_strn(prop->input.space + prop->input.pos,
             prop->input.size - prop->input.pos);
         cxstring nl = cx_strchr(input, '\n');
+        while (nl.length > 0) {
+            // check for line continuation
+            char previous = nl.ptr > input.ptr ? nl.ptr[-1] : prop->buffer.space[prop->buffer.size-1];
+            if (previous == continuation) {
+                // this nl is a line continuation, check the next newline
+                nl = cx_strchr(cx_strsubs(nl, 1), '\n');
+            } else {
+                break;
+            }
+        }
+        
         if (nl.length > 0) {
             // we add as much data to the rescue buffer as we need
             // to complete the line
@@ -120,19 +140,14 @@
             // still not enough data, copy input buffer to internal buffer
             if (cxBufferAppend(input.ptr, 1,
                 input.length, &prop->buffer) < input.length) {
-                return CX_PROPERTIES_BUFFER_ALLOC_FAILED;
+                return CX_PROPERTIES_BUFFER_ALLOC_FAILED; // LCOV_EXCL_LINE
             }
             // reset the input buffer (make way for a re-fill)
             cxBufferReset(&prop->input);
             return CX_PROPERTIES_INCOMPLETE_DATA;
         }
     }
-
-    char comment1 = prop->config.comment1;
-    char comment2 = prop->config.comment2;
-    char comment3 = prop->config.comment3;
-    char delimiter = prop->config.delimiter;
-
+   
     // get one line and parse it
     while (!cxBufferEof(current_buffer)) {
         const char *buf = current_buffer->space + current_buffer->pos;
@@ -145,6 +160,7 @@
         size_t delimiter_index = 0;
         size_t comment_index = 0;
         bool has_comment = false;
+        bool has_continuation = false;
 
         size_t i = 0;
         char c = 0;
@@ -159,6 +175,9 @@
                 if (delimiter_index == 0 && !has_comment) {
                     delimiter_index = i;
                 }
+            } else if (delimiter_index > 0 && c == continuation && i+1 < len && buf[i+1] == '\n') {
+                has_continuation = true;
+                i++;
             } else if (c == '\n') {
                 break;
             }
@@ -171,7 +190,7 @@
             assert(cxBufferEof(&prop->buffer));
             if (prop->buffer.space == NULL) {
                 // initialize a rescue buffer, if the user did not provide one
-                cxBufferInit(&prop->buffer, NULL, 256, NULL, CX_BUFFER_AUTO_EXTEND);
+                cxBufferInit(&prop->buffer, NULL, NULL, 256, CX_BUFFER_AUTO_EXTEND);
             } else {
                 // from a previous rescue there might be already read data
                 // reset the buffer to avoid unnecessary buffer extension
@@ -223,10 +242,53 @@
             k = cx_strtrim(k);
             val = cx_strtrim(val);
             if (k.length > 0) {
+                current_buffer->pos += i + 1; 
+                assert(current_buffer->pos <= current_buffer->size);
+                assert(current_buffer != &prop->buffer || current_buffer->pos == current_buffer->size);
+                
+                if (has_continuation) {
+                    char *ptr = (char*)val.ptr;
+                    if (current_buffer != &prop->buffer) {
+                        // move value to the rescue buffer
+                        if (prop->buffer.space == NULL) {
+                            cxBufferInit(&prop->buffer, NULL, NULL, 256, CX_BUFFER_AUTO_EXTEND);
+                        }
+                        prop->buffer.size = 0;
+                        prop->buffer.pos = 0;
+                        if (cxBufferWrite(val.ptr, 1, val.length, &prop->buffer) != val.length) {
+                            return CX_PROPERTIES_BUFFER_ALLOC_FAILED;
+                        }
+                        val.ptr = prop->buffer.space;
+                        ptr = prop->buffer.space;
+                    }
+                    // value.ptr is now inside the rescue buffer and we can
+                    // remove the continuation character from the value
+                    bool trim = false;
+                    size_t x = 0;
+                    for(size_t j=0;j<val.length;j++) {
+                        c = ptr[j];
+                        if (j+1 < val.length && c == '\\' && ptr[j+1] == '\n') {
+                            // skip continuation and newline character
+                            j++;
+                            trim = true; // enable trim in the next line
+                            continue;
+                        }
+                        if (j > x) {
+                            if (trim) {
+                                if (isspace((unsigned char)c)) {
+                                    continue;
+                                }
+                                trim = false;
+                            }
+                            ptr[x] = c;
+                        }
+                        x++;
+                    }
+                    val.length = x;
+                }
                 *key = k;
                 *value = val;
-                current_buffer->pos += i + 1;
-                assert(current_buffer->pos <= current_buffer->size);
+                
                 return CX_PROPERTIES_NO_ERROR;
             } else {
                 return CX_PROPERTIES_INVALID_EMPTY_KEY;
@@ -241,180 +303,96 @@
     return CX_PROPERTIES_NO_DATA;
 }
 
-static int cx_properties_sink_map(
-        cx_attr_unused CxProperties *prop,
-        CxPropertiesSink *sink,
-        cxstring key,
-        cxstring value
-) {
-    CxMap *map = sink->sink;
-    CxAllocator *alloc = sink->data;
-    cxmutstr v = cx_strdup_a(alloc, value);
-    int r = cxMapPut(map, key, v.ptr);
-    if (r != 0) cx_strfree_a(alloc, &v);
-    return r;
-}
-
-CxPropertiesSink cxPropertiesMapSink(CxMap *map) {
-    CxPropertiesSink sink;
-    sink.sink = map;
-    sink.data = (void*) cxDefaultAllocator;
-    sink.sink_func = cx_properties_sink_map;
-    return sink;
-}
+#ifndef CX_PROPERTIES_LOAD_FILL_SIZE
+#define CX_PROPERTIES_LOAD_FILL_SIZE 1024
+#endif
+const unsigned cx_properties_load_fill_size = CX_PROPERTIES_LOAD_FILL_SIZE;
+#ifndef CX_PROPERTIES_LOAD_BUF_SIZE
+#define CX_PROPERTIES_LOAD_BUF_SIZE 256
+#endif
+const unsigned cx_properties_load_buf_size = CX_PROPERTIES_LOAD_BUF_SIZE;
 
-static int cx_properties_read_string(
-        CxProperties *prop,
-        CxPropertiesSource *src,
-        cxstring *target
-) {
-    if (prop->input.space == src->src) {
-        // when the input buffer already contains the string
-        // we have nothing more to provide
-        target->length = 0;
-    } else {
-        target->ptr = src->src;
-        target->length = src->data_size;
+CxPropertiesStatus cx_properties_load(const CxAllocator *allocator,
+                                      cxstring filename, CxMap *target, CxPropertiesConfig config) {
+    if (allocator == NULL) {
+        allocator = cxDefaultAllocator;
     }
-    return 0;
-}
-
-static int cx_properties_read_file(
-        cx_attr_unused CxProperties *prop,
-        CxPropertiesSource *src,
-        cxstring *target
-) {
-    target->ptr = src->data_ptr;
-    target->length = fread(src->data_ptr, 1, src->data_size, src->src);
-    return ferror((FILE*)src->src);
-}
-
-static int cx_properties_read_init_file(
-        cx_attr_unused CxProperties *prop,
-        CxPropertiesSource *src
-) {
-    src->data_ptr = cxMallocDefault(src->data_size);
-    if (src->data_ptr == NULL) return 1;
-    return 0;
-}
 
-static void cx_properties_read_clean_file(
-        cx_attr_unused CxProperties *prop,
-        CxPropertiesSource *src
-) {
-    cxFreeDefault(src->data_ptr);
-}
-
-CxPropertiesSource cxPropertiesStringSource(cxstring str) {
-    CxPropertiesSource src;
-    src.src = (void*) str.ptr;
-    src.data_size = str.length;
-    src.data_ptr = NULL;
-    src.read_func = cx_properties_read_string;
-    src.read_init_func = NULL;
-    src.read_clean_func = NULL;
-    return src;
-}
-
-CxPropertiesSource cxPropertiesCstrnSource(const char *str, size_t len) {
-    CxPropertiesSource src;
-    src.src = (void*) str;
-    src.data_size = len;
-    src.data_ptr = NULL;
-    src.read_func = cx_properties_read_string;
-    src.read_init_func = NULL;
-    src.read_clean_func = NULL;
-    return src;
-}
+    // sanity check for the map
+    const bool use_cstring = cxCollectionStoresPointers(target);
+    if (!use_cstring && cxCollectionElementSize(target) != sizeof(cxmutstr)) {
+        return CX_PROPERTIES_MAP_ERROR;
+    }
 
-CxPropertiesSource cxPropertiesCstrSource(const char *str) {
-    CxPropertiesSource src;
-    src.src = (void*) str;
-    src.data_size = strlen(str);
-    src.data_ptr = NULL;
-    src.read_func = cx_properties_read_string;
-    src.read_init_func = NULL;
-    src.read_clean_func = NULL;
-    return src;
-}
+    // create a duplicate to guarantee zero-termination
+    cxmutstr fname = cx_strdup(filename);
+    if (fname.ptr == NULL) {
+        return CX_PROPERTIES_BUFFER_ALLOC_FAILED; // LCOV_EXCL_LINE
+    }
 
-CxPropertiesSource cxPropertiesFileSource(FILE *file, size_t chunk_size) {
-    CxPropertiesSource src;
-    src.src = file;
-    src.data_size = chunk_size;
-    src.data_ptr = NULL;
-    src.read_func = cx_properties_read_file;
-    src.read_init_func = cx_properties_read_init_file;
-    src.read_clean_func = cx_properties_read_clean_file;
-    return src;
-}
-
-CxPropertiesStatus cxPropertiesLoad(
-        CxProperties *prop,
-        CxPropertiesSink sink,
-        CxPropertiesSource source
-) {
-    assert(source.read_func != NULL);
-    assert(sink.sink_func != NULL);
-
-    // initialize reader
-    if (source.read_init_func != NULL) {
-        if (source.read_init_func(prop, &source)) {
-            return CX_PROPERTIES_READ_INIT_FAILED;
-        }
+    // open the file
+    FILE *f = fopen(fname.ptr, "r");
+    if (f == NULL) {
+        cx_strfree(&fname);
+        return CX_PROPERTIES_FILE_ERROR;
     }
 
-    // transfer the data from the source to the sink
+    // initialize the parser
+    char linebuf[cx_properties_load_buf_size];
+    char fillbuf[cx_properties_load_fill_size];
     CxPropertiesStatus status;
-    CxPropertiesStatus kv_status = CX_PROPERTIES_NO_DATA;
-    bool found = false;
+    CxProperties parser;
+    cxPropertiesInit(&parser, config);
+    cxPropertiesUseStack(&parser, linebuf, cx_properties_load_buf_size);
+
+    // read/fill/parse loop
+    status = CX_PROPERTIES_NO_DATA;
+    size_t keys_found = 0;
     while (true) {
-        // read input
-        cxstring input;
-        if (source.read_func(prop, &source, &input)) {
-            status = CX_PROPERTIES_READ_FAILED;
+        size_t r = fread(fillbuf, 1, cx_properties_load_fill_size, f);
+        if (ferror(f)) {
+            status = CX_PROPERTIES_FILE_ERROR;
+            break;
+        }
+        if (r == 0) {
             break;
         }
-
-        // no more data - break
-        if (input.length == 0) {
-            if (found) {
-                // something was found, check the last kv_status
-                if (kv_status == CX_PROPERTIES_INCOMPLETE_DATA) {
-                    status = CX_PROPERTIES_INCOMPLETE_DATA;
-                } else {
-                    status = CX_PROPERTIES_NO_ERROR;
-                }
-            } else {
-                // nothing found
-                status = CX_PROPERTIES_NO_DATA;
-            }
+        if (cxPropertiesFilln(&parser, fillbuf, r)) {
+            status = CX_PROPERTIES_BUFFER_ALLOC_FAILED;
             break;
         }
-
-        // set the input buffer and read the k/v-pairs
-        cxPropertiesFill(prop, input);
-
-        do {
-            cxstring key, value;
-            kv_status = cxPropertiesNext(prop, &key, &value);
-            if (kv_status == CX_PROPERTIES_NO_ERROR) {
-                found = true;
-                if (sink.sink_func(prop, &sink, key, value)) {
-                    kv_status = CX_PROPERTIES_SINK_FAILED;
+        cxstring key, value;
+        while (true) {
+            status = cxPropertiesNext(&parser, &key, &value);
+            if (status != CX_PROPERTIES_NO_ERROR) {
+                break;
+            } else {
+                cxmutstr v = cx_strdup_a(allocator, value);
+                if (v.ptr == NULL) {
+                    status = CX_PROPERTIES_MAP_ERROR;
+                    break;
                 }
+                void *mv = use_cstring ? (void*)v.ptr : &v;
+                if (cxMapPut(target, key, mv)) {
+                    cx_strfree(&v);
+                    status = CX_PROPERTIES_MAP_ERROR;
+                    break;
+                }
+                keys_found++;
             }
-        } while (kv_status == CX_PROPERTIES_NO_ERROR);
-
-        if (kv_status > CX_PROPERTIES_OK) {
-            status = kv_status;
+        }
+        if (status > CX_PROPERTIES_OK) {
             break;
         }
     }
 
-    if (source.read_clean_func != NULL) {
-        source.read_clean_func(prop, &source);
+    // cleanup and exit
+    fclose(f);
+    cxPropertiesDestroy(&parser);
+    cx_strfree(&fname);
+    if (status == CX_PROPERTIES_NO_DATA && keys_found > 0) {
+        return CX_PROPERTIES_NO_ERROR;
+    } else {
+        return status;
     }
-
-    return status;
 }
--- a/ucx/string.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/string.c	Fri Dec 19 17:53:18 2025 +0100
@@ -25,7 +25,8 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
-#ifdef MEMRCHR_NEED_GNU
+
+#ifdef WITH_MEMRCHR
 #define _GNU_SOURCE
 #endif
 
@@ -46,28 +47,6 @@
 #define cx_strcasecmp_impl strncasecmp
 #endif
 
-cxmutstr cx_mutstr(char *cstring) {
-    return (cxmutstr) {cstring, cstring == NULL ? 0 : strlen(cstring)};
-}
-
-cxmutstr cx_mutstrn(
-        char *cstring,
-        size_t length
-) {
-    return (cxmutstr) {cstring, length};
-}
-
-cxstring cx_str(const char *cstring) {
-    return (cxstring) {cstring, cstring == NULL ? 0 : strlen(cstring)};
-}
-
-cxstring cx_strn(
-        const char *cstring,
-        size_t length
-) {
-    return (cxstring) {cstring, length};
-}
-
 void cx_strfree(cxmutstr *str) {
     if (str == NULL) return;
     cxFreeDefault(str->ptr);
@@ -91,7 +70,7 @@
         cxstring src
 ) {
     if (cxReallocate(alloc, &dest->ptr, src.length + 1)) {
-        return 1;
+        return 1; // LCOV_EXCL_LINE
     }
 
     memcpy(dest->ptr, src.ptr, src.length);
@@ -137,7 +116,7 @@
     size_t slen = str.length;
     for (size_t i = 0; i < count; i++) {
         cxstring s = va_arg(ap, cxstring);
-        if (slen > SIZE_MAX - str.length) overflow = true;
+        if (slen > SIZE_MAX - s.length) overflow = true;
         slen += s.length;
     }
     va_end(ap);
@@ -156,10 +135,10 @@
     } else {
         newstr = cxRealloc(alloc, str.ptr, slen + 1);
     }
-    if (newstr == NULL) {
+    if (newstr == NULL) { // LCOV_EXCL_START
         va_end(ap2);
         return (cxmutstr) {NULL, 0};
-    }
+    } // LCOV_EXCL_STOP
     str.ptr = newstr;
 
     // concatenate strings
@@ -521,10 +500,12 @@
             cxMalloc(allocator, string.length + 1),
             string.length
     };
+    // LCOV_EXCL_START
     if (result.ptr == NULL) {
         result.length = 0;
         return result;
     }
+    // LCOV_EXCL_STOP
     memcpy(result.ptr, string.ptr, string.length);
     result.ptr[string.length] = '\0';
     return result;
--- a/ucx/tree.c	Sun Dec 07 20:16:59 2025 +0100
+++ b/ucx/tree.c	Fri Dec 19 17:53:18 2025 +0100
@@ -28,8 +28,6 @@
 
 #include "cx/tree.h"
 
-#include "cx/array_list.h"
-
 #include <assert.h>
 
 #define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))
@@ -352,7 +350,16 @@
         }
     } else {
         // node has children, push the first child onto the stack and enter it
-        cx_array_simple_add(iter->stack, children);
+        if (iter->stack_size >= iter->stack_capacity) {
+            const size_t newcap = iter->stack_capacity + 8;
+            if (cxReallocArrayDefault(&iter->stack, newcap, sizeof(void*))) {
+                // we cannot return an error in this function
+                abort(); // LCOV_EXCL_LINE
+            }
+            iter->stack_capacity = newcap;
+        }
+        iter->stack[iter->stack_size] = children;
+        iter->stack_size++;
         iter->node = children;
         iter->counter++;
     }
@@ -566,7 +573,7 @@
         ptrdiff_t loc_next
 ) {
     *cnode = cfunc(src, cdata);
-    if (*cnode == NULL) return 1;
+    if (*cnode == NULL) return 1;  // LCOV_EXCL_LINE
     cx_tree_zero_pointers(*cnode, cx_tree_ptr_locations);
 
     void *match = NULL;
@@ -627,7 +634,7 @@
 
         // create the new node
         void *new_node = cfunc(elem, cdata);
-        if (new_node == NULL) return processed;
+        if (new_node == NULL) return processed;  // LCOV_EXCL_LINE
         cx_tree_zero_pointers(new_node, cx_tree_ptr_locations);
 
         // start searching from current node
@@ -717,7 +724,7 @@
     }
 
     // otherwise, create iterator and hand over to other function
-    CxIterator iter = cxIterator(src, elem_size, num, false);
+    CxIterator iter = cxIterator(src, elem_size, num);
     return cx_tree_add_iter(cxIteratorRef(iter), num, sfunc,
                             cfunc, cdata, failed, root,
                             loc_parent, loc_children, loc_last_child,
@@ -731,18 +738,18 @@
     void *node;
     if (tree->root == NULL) {
         node = tree->node_create(data, tree);
-        if (node == NULL) return 1;
+        if (node == NULL) return 1;  // LCOV_EXCL_LINE
         cx_tree_zero_pointers(node, cx_tree_node_layout(tree));
         tree->root = node;
-        tree->size = 1;
+        tree->collection.size = 1;
         return 0;
     }
     int result = cx_tree_add(data, tree->search, tree->node_create,
                 tree, &node, tree->root, cx_tree_node_layout(tree));
     if (0 == result) {
-        tree->size++;
+        tree->collection.size++;
     } else {
-        cxFree(tree->allocator, node);
+        cxFree(tree->collection.allocator, node);
     }
     return result;
 }
@@ -758,7 +765,7 @@
         // use the first element from the iter to create the root node
         void **eptr = iter->current(iter);
         void *node = tree->node_create(*eptr, tree);
-        if (node == NULL) return 0;
+        if (node == NULL) return 0;  // LCOV_EXCL_LINE
         cx_tree_zero_pointers(node, cx_tree_node_layout(tree));
         tree->root = node;
         ins = 1;
@@ -767,9 +774,9 @@
     void *failed;
     ins += cx_tree_add_iter(iter, n, tree->search, tree->node_create,
                                   tree, &failed, tree->root, cx_tree_node_layout(tree));
-    tree->size += ins;
+    tree->collection.size += ins;
     if (ins < n) {
-        cxFree(tree->allocator, failed);
+        cxFree(tree->collection.allocator, failed);
     }
     return ins;
 }
@@ -780,7 +787,7 @@
         const void *data,
         size_t depth
 ) {
-    if (tree->root == NULL) return NULL;
+    if (tree->root == NULL) return NULL;  // LCOV_EXCL_LINE
 
     void *found;
     if (0 == cx_tree_search_data(
@@ -818,24 +825,21 @@
     assert(search_func != NULL);
     assert(search_data_func != NULL);
 
-    CxTree *tree = cxMalloc(allocator, sizeof(CxTree));
-    if (tree == NULL) return NULL;
+    CxTree *tree = cxZalloc(allocator, sizeof(CxTree));
+    if (tree == NULL) return NULL;  // LCOV_EXCL_LINE
 
     tree->cl = &cx_tree_default_class;
-    tree->allocator = allocator;
+    tree->collection.allocator = allocator;
     tree->node_create = create_func;
     tree->search = search_func;
     tree->search_data = search_data_func;
-    tree->simple_destructor = NULL;
-    tree->advanced_destructor = (cx_destructor_func2) cxFree;
-    tree->destructor_data = (void *) allocator;
+    tree->collection.advanced_destructor = (cx_destructor_func2) cxFree;
+    tree->collection.destructor_data = (void *) allocator;
     tree->loc_parent = loc_parent;
     tree->loc_children = loc_children;
     tree->loc_last_child = loc_last_child;
     tree->loc_prev = loc_prev;
     tree->loc_next = loc_next;
-    tree->root = NULL;
-    tree->size = 0;
 
     return tree;
 }
@@ -845,7 +849,7 @@
     if (tree->root != NULL) {
         cxTreeClear(tree);
     }
-    cxFree(tree->allocator, tree);
+    cxFree(tree->collection.allocator, tree);
 }
 
 CxTree *cxTreeCreateWrapped(const CxAllocator *allocator, void *root,
@@ -856,47 +860,41 @@
     }
     assert(root != NULL);
 
-    CxTree *tree = cxMalloc(allocator, sizeof(CxTree));
-    if (tree == NULL) return NULL;
+    CxTree *tree = cxZalloc(allocator, sizeof(CxTree));
+    if (tree == NULL) return NULL;  // LCOV_EXCL_LINE
 
     tree->cl = &cx_tree_default_class;
     // set the allocator anyway, just in case...
-    tree->allocator = allocator;
-    tree->node_create = NULL;
-    tree->search = NULL;
-    tree->search_data = NULL;
-    tree->simple_destructor = NULL;
-    tree->advanced_destructor = NULL;
-    tree->destructor_data = NULL;
+    tree->collection.allocator = allocator;
     tree->loc_parent = loc_parent;
     tree->loc_children = loc_children;
     tree->loc_last_child = loc_last_child;
     tree->loc_prev = loc_prev;
     tree->loc_next = loc_next;
     tree->root = root;
-    tree->size = cxTreeSubtreeSize(tree, root);
+    tree->collection.size = cxTreeSubtreeSize(tree, root);
     return tree;
 }
 
 void cxTreeSetParent(CxTree *tree, void *parent, void *child) {
     size_t loc_parent = tree->loc_parent;
     if (tree_parent(child) == NULL) {
-        tree->size++;
+        tree->collection.size++;
     }
     cx_tree_link(parent, child, cx_tree_node_layout(tree));
 }
 
 void cxTreeAddChildNode(CxTree *tree, void *parent, void *child) {
     cx_tree_link(parent, child, cx_tree_node_layout(tree));
-    tree->size++;
+    tree->collection.size++;
 }
 
 int cxTreeAddChild(CxTree *tree, void *parent, const void *data) {
     void *node = tree->node_create(data, tree);
-    if (node == NULL) return 1;
+    if (node == NULL) return 1; // LCOV_EXCL_LINE
     cx_tree_zero_pointers(node, cx_tree_node_layout(tree));
     cx_tree_link(parent, node, cx_tree_node_layout(tree));
-    tree->size++;
+    tree->collection.size++;
     return 0;
 }
 
@@ -911,7 +909,7 @@
 size_t cxTreeInsertArray(CxTree *tree, const void *data, size_t elem_size, size_t n) {
     if (n == 0) return 0;
     if (n == 1) return 0 == cxTreeInsert(tree, data) ? 1 : 0;
-    CxIterator iter = cxIterator(data, elem_size, n, false);
+    CxIterator iter = cxIterator(data, elem_size, n);
     return cxTreeInsertIter(tree, cxIteratorRef(iter), n);
 }
 
@@ -948,7 +946,7 @@
 }
 
 size_t cxTreeSize(CxTree *tree) {
-    return tree->size;
+    return tree->collection.size;
 }
 
 size_t cxTreeDepth(CxTree *tree) {
@@ -1002,7 +1000,7 @@
     if (loc_last_child >= 0) tree_last_child(node) = NULL;
 
     // the tree now has one member less
-    tree->size--;
+    tree->collection.size--;
 
     return 0;
 }
@@ -1010,12 +1008,12 @@
 void cxTreeRemoveSubtree(CxTree *tree, void *node) {
     if (node == tree->root) {
         tree->root = NULL;
-        tree->size = 0;
+        tree->collection.size = 0;
         return;
     }
     size_t subtree_size = cxTreeSubtreeSize(tree, node);
     cx_tree_unlink(node, cx_tree_node_layout(tree));
-    tree->size -= subtree_size;
+    tree->collection.size -= subtree_size;
 }
 
 int cxTreeDestroyNode(
@@ -1025,12 +1023,7 @@
 ) {
     int result = cxTreeRemoveNode(tree, node, relink_func);
     if (result == 0) {
-        if (tree->simple_destructor) {
-            tree->simple_destructor(node);
-        }
-        if (tree->advanced_destructor) {
-            tree->advanced_destructor(tree->destructor_data, node);
-        }
+        cx_invoke_destructor(tree, node);
         return 0;
     } else {
         return result;
@@ -1045,15 +1038,10 @@
     );
     cx_foreach(void *, child, iter) {
         if (iter.exiting) {
-            if (tree->simple_destructor) {
-                tree->simple_destructor(child);
-            }
-            if (tree->advanced_destructor) {
-                tree->advanced_destructor(tree->destructor_data, child);
-            }
+            cx_invoke_destructor(tree, child);
         }
     }
-    tree->size -= iter.counter;
+    tree->collection.size -= iter.counter;
     if (node == tree->root) {
         tree->root = NULL;
     }
@@ -1071,6 +1059,7 @@
         cxFreeDefault(q);
         q = next;
     }
+    visitor->queue_next = visitor->queue_last = NULL;
 }
 
 CxTreeIterator cxTreeIterateSubtree(CxTree *tree, void *node, bool visit_on_exit) {

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