implemented shrink_to_fit for vector

src/main.c

@@ -6,13 +6,16 @@
 
 int main() {
   vector *vec = vec_create(sizeof(int));
-  for (int x = 0; x < 10; x++) {
+  for (int x = 0; x < 100; x++) {
     vec_push_back(vec, &x);
   }
   int i = 99999999;
   vec_push_index(vec, &i, 5);
   vec_push_front(vec, &i);
-  for (int x = 0; x < 12; x++) {
+  printf("Capacity before shrink: %zu | ", vec_capacity(vec));
+  vec_shrink_to_fit(vec);
+  printf("Capacity after: %zu\n", vec_capacity(vec));
+  for (int x = 0; x < 102; x++) {
     printf("%d ", *(int *)vec_get(vec, x));
   }
   printf("\n");

src/vec.c

@@ -38,6 +38,12 @@ void vec_grow(vector *vec) {
   assert(vec->elements != NULL);
 }
 
+void vec_shrink_to_fit(vector *vec) {
+  assert(vec != NULL);
+  vec->capacity = vec->size;
+  vec->elements = reallocarray(vec->elements, vec->size, vec->element_size);
+}
+
 void vec_push_back(vector *vec, void *data) {
   assert(vec != NULL);
   vec_grow(vec);
@@ -69,3 +75,13 @@ void *vec_get(vector *vec, uint index) {
   assert(index <= vec->size);
   return vec->elements + index * vec->element_size;
 }
+
+size_t vec_size(vector *vec) {
+  assert(vec != NULL);
+  return vec->size;
+}
+
+size_t vec_capacity(vector *vec) {
+  assert(vec != NULL);
+  return vec->capacity;
+}

src/vec.h

@@ -8,6 +8,7 @@ void vec_destroy(vector *vec);
 
 // Checks and grows vector only if necessary
 void vec_grow(vector *vec);
+void vec_shrink_to_fit(vector *vec);
 
 // Assumes data is the same size as the element size
 // Which means you can only push one element at a time
@@ -16,3 +17,5 @@ void vec_push_front(vector *vec, void *data);
 void vec_push_index(vector *vec, void *data, uint index);
 
 void* vec_get(vector *vec, uint index);
+size_t vec_size(vector *vec);
+size_t vec_capacity(vector *vec);