diff -r a10c3e127050 -r bb144d08cd44 src/linked_list.c
--- a/src/linked_list.c	Sun Oct 03 13:07:48 2021 +0200
+++ b/src/linked_list.c	Sun Oct 03 14:06:57 2021 +0200
@@ -29,6 +29,7 @@
 #include "cx/linked_list.h"
 #include <stdint.h>
 #include <string.h>
+#include <assert.h>
 
 /* LOW LEVEL LINKED LIST FUNCTIONS */
 
@@ -61,16 +62,11 @@
     }
 }
 
-int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node) {
+void cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node) {
     void *last = cx_linked_list_last(begin, end, loc_next);
     if (last == NULL) {
-        if (begin == NULL) {
-            // no current list and no begin ptr to write to - we don't find something to append to
-            return 1;
-        } else {
-            // start fresh list
-            *begin = new_node;
-        }
+        assert(begin != NULL);
+        *begin = new_node;
     } else {
         // if there is a last node, update its next pointer
         void **next = CX_LL_PTR(last, loc_next);
@@ -87,8 +83,6 @@
         void **prev = CX_LL_PTR(new_node, loc_prev);
         *prev = last;
     }
-
-    return 0;
 }
 
 /* HIGH LEVEL LINKED LIST IMPLEMENTATION */