extern void ChangeVehicleViewWindow(VehicleID from_index, VehicleID to_index);

/**

 * Figure out if two engines got at least one type of cargo in common (refitting if needed)

 * @param engine_a one of the EngineIDs

 * @param engine_b the other EngineID

 * @return true if they can both carry the same type of cargo (or at least one of them got no capacity at all)

 */

static bool EnginesHaveCargoInCommon(EngineID engine_a, EngineID engine_b)

{

	CargoTypes available_cargoes_a = GetUnionOfArticulatedRefitMasks(engine_a, true);

	CargoTypes available_cargoes_b = GetUnionOfArticulatedRefitMasks(engine_b, true);

/**

 * Get the EngineID of the replacement for a vehicle

 * @param v The vehicle to find a replacement for

 * @param c The vehicle's owner (it's faster to forward the pointer than refinding it)

 * @param always_replace Always replace, even if not old.

 * @return Error if the engine to build is not available

 */

static CommandCost GetNewEngineType(const Vehicle *v, const Company *c, bool always_replace, EngineID &e)

{

	assert(v->type != VEH_TRAIN || !v->IsArticulatedPart());