diff --git a/map.c b/map.c
index 67c1357..9d32da0 100644
--- a/map.c
+++ b/map.c
@@ -1,25 +1,40 @@
 #include "cig.h"
+#include <assert.h>
 
 static inline int mapping_cap(int capacity) {
 	return capacity * 2;
 }
 
-void *map_create_func(
-	map_create_func_args_t args
-) {
+typedef struct internal_map_sizes {
+	int bytes;
+	int cap_of_items_arr;
+} internal_map_sizes_t;
 
+internal_map_sizes_t internal_map_sizes(int capacity, int itemsize) {
 	const size_t cap_of_index_arr =
-		sizeof(int) * mapping_cap(args.initial_capacity);
+		sizeof(int) * mapping_cap(capacity);
 	const size_t INC = ALIGN_OF(int);
-	const size_t SIZE = args.itemsize * args.initial_capacity;
+	const size_t SIZE = itemsize * capacity;
 	const size_t cap_of_items_arr = (SIZE + INC - 1) / INC;
 	const size_t bytes =
 		sizeof(map_header_t) + cap_of_items_arr + cap_of_index_arr;
+	return (internal_map_sizes_t){
+		.bytes=bytes,
+		.cap_of_items_arr=cap_of_items_arr,
+	};
+}
 
+void *map_create_func(
+	map_create_func_args_t args
+) {
+	internal_map_sizes_t sizes = internal_map_sizes(
+		args.initial_capacity,
+		args.itemsize
+	);
 	map_header_t *header =
 		allocator_alloc_func(
 			args.allocator,
-			bytes,
+			sizes.bytes,
 			args.file,
 			args.line
 		);
@@ -31,7 +46,7 @@ void *map_create_func(
 	header->allocator = args.allocator;
 	header->hash = args.hash;
 	header->equals = args.equals;
-	header->mapping_arr = (int*) &header->bytes[cap_of_items_arr];
+	header->mapping_arr = (int*) &header->bytes[sizes.cap_of_items_arr];
 	header->mapping_capacity = mapping_cap(args.initial_capacity);
 
 	for ( int i = 0; i < header->mapping_capacity; i++ ) {
@@ -41,7 +56,15 @@ void *map_create_func(
 	return header->bytes;
 }
 
-void map_grow(void *this) {
+void *map_grow_func(void *this, const char *file, int line) {
+	map_header_t *header = PTR_FROM_FIELD_PTR(map_header_t, bytes, this);
+	allocator_t allocator = header->allocator;
+	const int new_size = 0; // TODO!!!
+	header = allocator_resize_func(allocator, header, new_size, file, line);
+	// TODO!!!
+	assert(false && "TODO");
+
+	return header->bytes;
 }
 
 int map_len(void *this) {