case WM_WINDOWPOSCHANGING: {

WINDOWPOS* p_wnd_pos = reinterpret_cast<WINDOWPOS*>(_l_param);

if (nullptr != p_wnd_pos) {

p_wnd_pos->cx = {desired_width};

p_wnd_pos->cy = {desired_height};

}

return 0; // important: returned result means the message is handled;

} break;