SWAP_WRAPPER
if (swap_func == SWAP_WRAPPER) {
if (swap_func == SWAP_WRAPPER && !((struct wrapper *)priv)->swap)
return __sort_r(base, num, size, _CMP_WRAPPER, SWAP_WRAPPER, &w, false);
return __sort_r(base, num, size, _CMP_WRAPPER, SWAP_WRAPPER, &w, true);