Function EngineIntroDateSorter

src/build_vehicle_gui.cpp:129–138

* Determines order of engines by introduction date * @param a first engine to compare * @param b second engine to compare * @return for descending order: returns true if a < b. Vice versa for ascending order */

 * @return for descending order: returns true if a < b. Vice versa for ascending order
 */
static bool EngineIntroDateSorter(const GUIEngineListItem &a, const GUIEngineListItem &b)
{
	const auto va = Engine::Get(a.engine_id)->intro_date;
	const auto vb = Engine::Get(b.engine_id)->intro_date;
	const auto r = va - vb;

	/* Use EngineID to sort instead since we want consistent sorting */
	if (r == 0) return EngineNumberSorter(a, b);
	return _engine_sort_direction ? r > 0 : r < 0;
}

/* cached values for EngineNameSorter to spare many GetString() calls */
static EngineID _last_engine[2] = { EngineID::Invalid(), EngineID::Invalid() };