#define vec_remove_and_free(v, cnt, free_func) \
do { \
free_func((v)->d[cnt]); \
for (size_t _i = cnt; _i < (v)->len; _i++) { \
for (size_t _i = cnt; _i < (v)->len - 1; _i++) { \
(v)->d[_i] = (v)->d[_i + 1]; \
} \
(v)->len--; \