Add cvec_get(...)

main.c

@@ -41,6 +41,16 @@ int cvec_new(cvec *dest, size_t elem_size)
     return 0;
 }
 
+int cvec_get(void *dest, cvec src, size_t elem_idx)
+{
+    if (elem_idx >= src.elem_count)
+        return -1;
+
+    memcpy(dest, src.elem_storage + elem_idx * src.elem_size, src.elem_size);
+
+    return 0;
+}
+
 int cvec_extend(cvec *dest)
 {
     dest->elem_count_cap *= 2;