# HG changeset patch
# User Mike Becker <universe@uap-core.de>
# Date 1612728210 -3600
# Node ID a34b93911956878dc9a40e39afd9fa721bdd7c84
# Parent  e6a8f7fb0c4557b1de13b14721c7f2d3fdbea763
use named fields to access node memory

diff -r e6a8f7fb0c45 -r a34b93911956 src/cx/linked_list.h
--- a/src/cx/linked_list.h	Sun Feb 07 20:37:20 2021 +0100
+++ b/src/cx/linked_list.h	Sun Feb 07 21:03:30 2021 +0100
@@ -34,7 +34,7 @@
 
 void *cx_linked_list_last(void **begin, void **end, ptrdiff_t loc_next);
 
-int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_next, ptrdiff_t loc_prev, void *newnode);
+int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *newnode);
 
 CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t itemsize);
 
diff -r e6a8f7fb0c45 -r a34b93911956 src/linked_list.c
--- a/src/linked_list.c	Sun Feb 07 20:37:20 2021 +0100
+++ b/src/linked_list.c	Sun Feb 07 21:03:30 2021 +0100
@@ -51,7 +51,7 @@
     }
 }
 
-int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_next, ptrdiff_t loc_prev, void *newnode) {
+int cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *newnode) {
     // TODO: how do we report error messages?
     if (loc_next < 0 || (begin == NULL && end == NULL)) {
         return 1;
@@ -79,6 +79,12 @@
 
 /* HIGH LEVEL LINKED LIST IMPLEMENTATION */
 
+struct cx_linked_list_node {
+    void *prev;
+    void *next;
+    int payload;
+};
+
 typedef struct {
     void *begin;
     void *end;
@@ -88,24 +94,19 @@
     cx_linked_list *listdata = list->listdata;
     CxAllocator allocator = list->allocator;
 
-    /*
-     * Memory layout:
-     * next : sizeof(void*)
-     * prev : sizeof(void*)
-     * data : itemsize
-     */
-    void *node = cxMalloc(allocator,2*sizeof(void*)+list->itemsize);
+    struct cx_linked_list_node *node = cxMalloc(allocator,
+            sizeof(struct cx_linked_list_node) - sizeof(int) + list->itemsize);
     if (node == NULL)
         return 1;
 
-    memset(node, 0, sizeof(void*));
-    memcpy(node+2, elem, list->itemsize);
+    node->next = NULL;
+    memcpy(&node->payload, elem, list->itemsize);
 
     int ret = cx_linked_list_add(
             &listdata->begin,
             &listdata->end,
-            0,
-            sizeof(void*),
+            offsetof(struct cx_linked_list_node, prev),
+            offsetof(struct cx_linked_list_node, next),
             node
     );
     if (ret == 0) {