Function luaM_shrinkvector_

3rd/lua-5.4.3/src/lmem.c:110–119

** In prototypes, the size of the array is also its number of ** elements (to save memory). So, if it cannot shrink an array ** to its number of elements, the only option is to raise an ** error. */

** error.
*/
void *luaM_shrinkvector_ (lua_State *L, void *block, int *size,
                          int final_n, int size_elem) {
  void *newblock;
  size_t oldsize = cast_sizet((*size) * size_elem);
  size_t newsize = cast_sizet(final_n * size_elem);
  lua_assert(newsize <= oldsize);
  newblock = luaM_saferealloc_(L, block, oldsize, newsize);
  *size = final_n;
  return newblock;
}

/* }================================================================== */