Refactor set, add attaching functional

examples/set.c

@@ -3,7 +3,7 @@
 
 #include <assert.h>
 #include <stdio.h>
-#include "../include/extra/set.h"
+#include "../include/set.h"
 
 typedef vtype_set vset_t;
 
@@ -22,6 +22,7 @@ int print_value(const void* value, vtype type, void* data) {
 int main(int argc, char** argv) {
 
     vset_t set;
+    int   a, b;
 
     vset_init(&set, VTYPE_INT32);
 
@@ -29,8 +30,11 @@ int main(int argc, char** argv) {
         vset_push(&set, i);
     }
 
-    vset_get(&set, 13, "Get value:", print_value);
-    vset_pop(&set, 18, "Pop value:", print_value);
+    a = 13;
+    b = 18;
+
+    vset_get(&set, a, "Get value:", print_value);
+    vset_pop(&set, b, "Pop value:", print_value);
 
     vset_foreach(&set, "Foreach loop:", print_value);