diff -r 9138acaa494b -r af6be1e123aa src/linked_list.c
--- a/src/linked_list.c	Tue Dec 28 17:24:18 2021 +0100
+++ b/src/linked_list.c	Tue Dec 28 17:38:02 2021 +0100
@@ -57,19 +57,19 @@
 }
 
 size_t cx_linked_list_find(
-        void *start,
+        void const *start,
         ptrdiff_t loc_advance,
         ptrdiff_t loc_data,
         bool follow_ptr,
         CxListComparator cmp_func,
-        void *elem
+        void const *elem
 ) {
     assert(start != NULL);
     assert(loc_advance >= 0);
     assert(loc_data >= 0);
     assert(cmp_func);
 
-    void *node = start;
+    void const *node = start;
     size_t index = 0;
     do {
         void *current = ll_data(node);
@@ -268,7 +268,7 @@
 }
 
 size_t cx_linked_list_size(
-        void *node,
+        void const *node,
         ptrdiff_t loc_next
 ) {
     assert(loc_next >= 0);
@@ -397,14 +397,14 @@
 }
 
 int cx_linked_list_compare(
-        void *begin_left,
-        void *begin_right,
+        void const *begin_left,
+        void const *begin_right,
         ptrdiff_t loc_advance,
         ptrdiff_t loc_data,
         bool follow_ptr,
         CxListComparator cmp_func
 ) {
-    void *left = begin_left, *right = begin_right;
+    void const *left = begin_left, *right = begin_right;
 
     while (left != NULL && right != NULL) {
         int result = cmp_func(ll_data(left), ll_data(right));
@@ -469,7 +469,7 @@
 } cx_linked_list;
 
 static cx_linked_list_node *cx_ll_node_at(
-        cx_linked_list *list,
+        cx_linked_list const *list,
         size_t index
 ) {
     if (index >= list->base.size) {
@@ -484,7 +484,7 @@
 static int cx_ll_insert(
         cx_list_s *list,
         size_t index,
-        void *elem
+        void const *elem
 ) {
     // out-of bounds check
     if (index > list->size) return 1;
@@ -520,7 +520,7 @@
 
 static int cx_ll_add(
         cx_list_s *list,
-        void *elem
+        void const *elem
 ) {
     return cx_ll_insert(list, list->size, elem);
 }
@@ -528,14 +528,14 @@
 static int cx_pll_insert(
         cx_list_s *list,
         size_t index,
-        void *elem
+        void const *elem
 ) {
     return cx_ll_insert(list, index, &elem);
 }
 
 static int cx_pll_add(
         cx_list_s *list,
-        void *elem
+        void const *elem
 ) {
     return cx_ll_insert(list, list->size, &elem);
 }
@@ -564,7 +564,7 @@
 }
 
 static void *cx_ll_at(
-        cx_list_s *list,
+        cx_list_s const *list,
         size_t index
 ) {
     cx_linked_list *ll = (cx_linked_list *) list;
@@ -573,7 +573,7 @@
 }
 
 static void *cx_pll_at(
-        cx_list_s *list,
+        cx_list_s const *list,
         size_t index
 ) {
     cx_linked_list *ll = (cx_linked_list *) list;
@@ -582,8 +582,8 @@
 }
 
 static size_t cx_ll_find(
-        cx_list_s *list,
-        void *elem
+        cx_list_s const *list,
+        void const *elem
 ) {
     return cx_linked_list_find(((cx_linked_list *) list)->begin,
                                CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
@@ -591,8 +591,8 @@
 }
 
 static size_t cx_pll_find(
-        cx_list_s *list,
-        void *elem
+        cx_list_s const *list,
+        void const *elem
 ) {
     return cx_linked_list_find(((cx_linked_list *) list)->begin,
                                CX_LL_LOC_NEXT, CX_LL_LOC_DATA,
@@ -614,8 +614,8 @@
 }
 
 static int cx_ll_compare(
-        cx_list_s *list,
-        cx_list_s *other
+        cx_list_s const *list,
+        cx_list_s const *other
 ) {
     cx_linked_list *left = (cx_linked_list *) list;
     cx_linked_list *right = (cx_linked_list *) other;
@@ -625,8 +625,8 @@
 }
 
 static int cx_pll_compare(
-        cx_list_s *list,
-        cx_list_s *other
+        cx_list_s const *list,
+        cx_list_s const *other
 ) {
     cx_linked_list *left = (cx_linked_list *) list;
     cx_linked_list *right = (cx_linked_list *) other;
@@ -703,7 +703,7 @@
         CxListComparator comparator,
         size_t item_size,
         size_t num_items,
-        const void *array
+        void const *array
 ) {
     CxList list = cxLinkedListCreate(allocator, comparator, item_size);
     if (list == NULL) return NULL;