diff -r bf3695fee719 -r 481802342fdf ucx/stack.c
--- a/ucx/stack.c	Mon Feb 04 14:11:57 2019 +0100
+++ b/ucx/stack.c	Mon Feb 04 17:17:48 2019 +0100
@@ -120,13 +120,15 @@
         return;
     }
     
-    size_t len = ucx_stack_topsize(stack);
-    if (len > n) {
-        len = n;
+    if (dest) {
+        size_t len = ucx_stack_topsize(stack);
+        if (len > n) {
+            len = n;
+        }
+
+        memcpy(dest, stack->top, len);
     }
     
-    memcpy(dest, stack->top, len);
-    
     ucx_stack_free(stack, stack->top);
 }
 
@@ -142,3 +144,22 @@
         return 0;
     }
 }
+
+void *ucx_stack_push(UcxStack *stack, size_t n, const void *data) {
+    void *space = ucx_stack_malloc(stack, n);
+    if (space) {
+        memcpy(space, data, n);
+    }
+    return space;
+}
+
+void *ucx_stack_pusharr(UcxStack *stack,
+        size_t nelem, size_t elsize, const void *data) {
+    
+    // skip the memset by using malloc
+    void *space = ucx_stack_malloc(stack, nelem*elsize);
+    if (space) {
+        memcpy(space, data, nelem*elsize);
+    }
+    return space;
+}