diff --git a/containers/named_array.c b/containers/named_array.c
index c028e96..bbfd66f 100644
--- a/containers/named_array.c
+++ b/containers/named_array.c
@@ -12,6 +12,8 @@
 
 #include "named_array.h"
 
+#define assert__(x) for ( ; !(x) ; assert(x) )
+
 void named_array_init(NamedArray* array, unsigned int element_size, unsigned int max_elements) {
     array->element_size = element_size;
     array->max_element_count = max_elements;
@@ -28,6 +30,7 @@ void named_array_init(NamedArray* array, unsigned int element_size, unsigned int
     array->used_markers = (unsigned char*) malloc(array->marker_count);
 #endif
     memset(array->used_markers, 0, sizeof(unsigned char) * array->marker_count);
+    memset(array->elements, 0, element_size * max_elements);
 }
 
 char named_array_used(NamedArray* array, unsigned int id) {
@@ -56,6 +59,17 @@ void* named_array_alloc(NamedArray* array, unsigned int* new_id) {
     return NULL;
 }
 
+#define BYTE_TO_BINARY_PATTERN "%c%c%c%c%c%c%c%c"
+#define BYTE_TO_BINARY(byte)  \
+  (byte & 0x80 ? '1' : '0'), \
+  (byte & 0x40 ? '1' : '0'), \
+  (byte & 0x20 ? '1' : '0'), \
+  (byte & 0x10 ? '1' : '0'), \
+  (byte & 0x08 ? '1' : '0'), \
+  (byte & 0x04 ? '1' : '0'), \
+  (byte & 0x02 ? '1' : '0'), \
+  (byte & 0x01 ? '1' : '0') 
+
 void* named_array_reserve(NamedArray* array, unsigned int id) {
     if(!named_array_used(array, id)) {
         unsigned int j = (id % 8);
@@ -63,6 +77,11 @@ void* named_array_reserve(NamedArray* array, unsigned int id) {
 
         assert(!named_array_used(array, id));
         array->used_markers[i] |= (unsigned char) 1 << j;
+        
+        assert__(named_array_used(array, id)) {
+            printf("%s: id %d is not used in [%d,%d] = "BYTE_TO_BINARY_PATTERN"\n",__func__,id,i,j, BYTE_TO_BINARY(array->used_markers[i])); 
+        }
+
         assert(named_array_used(array, id));
 
         unsigned char* ptr = &array->elements[id * array->element_size];