More fixes for event handlers meta programming logic

SDL2pp/Private/EventHandlerFunctor.hh

@@ -30,13 +30,6 @@ namespace SDL2pp {
  * This is code not to be used directly by users of SDL2pp.
  */
 namespace Private {
-	/*
-	 * Helper alias to help identify a functor object with the correct signature
-	 * to be used as an event handler.
-	 */
-	template <typename EventType>
-	using EventHandlerFunctorSignature = std::function<void(const EventType &)>;
-
 	/*
 	 * Templated class to identify a class that is not an event handler functor.
 	 */
@@ -53,7 +46,7 @@ namespace Private {
 		EventHandlerType,
 		EventType,
 		typename std::enable_if<
-			std::is_convertible<EventHandlerType, EventHandlerFunctorSignature<EventType>>::value
+			std::is_convertible<EventHandlerType, std::function<void(EventType)>>::value
 		>::type
 	> : std::true_type { };
 }

SDL2pp/Private/EventHandlerObject.hh

@@ -29,15 +29,6 @@ namespace SDL2pp {
  * This is code not to be used directly by users of SDL2pp.
  */
 namespace Private {
-	/*
-	 * Templated class to detect if a given type can handle a given event.
-	 */
-	template <typename EventHandlerType, typename EventType>
-	struct HasEventHandlerMethod : std::is_same<
-		decltype(std::declval<EventHandlerType>().HandleEvent(std::declval<const EventType &>())),
-		void
-	> { };
-	
 	/*
 	 * Templated class to identify a class that is not an event handler object.
 	 */
@@ -47,15 +38,18 @@ namespace Private {
 	/*
 	 * Templated class to identify a class that is an event handler object, the
 	 * way this is done is by verifying that an instance of EventHandlerType has
-	 * the "HandleEvent" member function which received a "const EventType &"
+	 * the "HandleEvent" member function which received a "EventType" and
-	 * and returns void.
+	 * returns void.
 	 */
 	template <typename EventHandlerType, typename EventType>
 	struct IsEventHandlerObject<
 		EventHandlerType,
 		EventType,
 		typename std::enable_if<
-			HasEventHandlerMethod<EventHandlerType, EventType>::value
+			std::is_same<
+				decltype(std::declval<EventHandlerType>().HandleEvent(std::declval<EventType>())),
+				void
+			>::value
 		>::type
 	> : std::true_type { };
 }

tests/test_eventhandler.cc

@@ -4,66 +4,66 @@
 
 using namespace SDL2pp::Private;
 
-void EventHandlerFunction(const SDL_Event &);
+void EventHandlerFunction(SDL_Event);
 
-struct EventHandlerOperator {
+struct EventHandlerFunctor {
 	void operator()(SDL_Event);
 };
 
 struct EventHandler {
-	void HandleEvent(const SDL_Event &);
-};
-
-struct InvalidEventHandler {
 	void HandleEvent(SDL_Event);
 };
 
+struct InvalidEventHandler {
+	void handleEvent(SDL_Event);
+};
+
 int main(int, char*[]) {
-	auto lambda = [](const SDL_Event &) { };
+	auto lambda = [](SDL_Event) { };
 
 	// Test IsEventHandlerFunctor
 	static_assert(
 		IsEventHandlerFunctor<decltype(EventHandlerFunction), SDL_Event>::value,
-		"IsEventHandlerFunctor<> should accept functions like void(const SDL_Event &)"
+		"IsEventHandlerFunctor<> should accept functions like void(SDL_Event)"
 	);
 	static_assert(
 		IsEventHandlerFunctor<decltype(lambda), SDL_Event>::value,
-		"IsEventHandlerFunctor<> should accept functions like void(const SDL_Event &)"
+		"IsEventHandlerFunctor<> should accept functions like void(SDL_Event)"
 	);
 	static_assert(
-		!IsEventHandlerFunctor<EventHandlerOperator, SDL_Event>::value,
+		IsEventHandlerFunctor<EventHandlerFunctor, SDL_Event>::value,
-		"IsEventHandlerFunctor<> shouldn't accept a class with operator(const SDL_Event &)"
+		"IsEventHandlerFunctor<> shouldn accept a class with operator(SDL_Event)"
 	);
 	
 	// Test IsEventHandlerObject
 	static_assert(
 		IsEventHandlerObject<EventHandler, SDL_Event>::value,
-		"IsEventHandlerObject<> should accept a class with HandleEvent(const SDL_Event &)"
+		"IsEventHandlerObject<> should accept a class with HandleEvent(SDL_Event)"
 	);
 	static_assert(
 		!IsEventHandlerObject<InvalidEventHandler, SDL_Event>::value,
-		"IsEventHandlerObject<> shouldn't accept a class with a different HandleEvent() signature"
+		"IsEventHandlerObject<> shouldn't accept a class without a valid signature"
 	);
 	
 	// Test IsEventHandler
 	static_assert(
 		IsEventHandler<decltype(EventHandlerFunction), SDL_Event>::value,
-		"IsEventHandler<> should accept functions like void(const SDL_Event &)"
+		"IsEventHandler<> should accept functions like void(SDL_Event)"
 	);
 	static_assert(
 		IsEventHandler<decltype(lambda), SDL_Event>::value,
-		"IsEventHandler<> should accept functions like void(const SDL_Event &)"
+		"IsEventHandler<> should accept functions like void(SDL_Event)"
+	);
+	static_assert(
+		IsEventHandler<EventHandlerFunctor, SDL_Event>::value,
+		"IsEventHandler<> should accept a class with operator(SDL_Event)"
 	);
 	static_assert(
 		IsEventHandler<EventHandler, SDL_Event>::value,
-		"IsEventHandler<> should accept a class with HandleEvent(const SDL_Event &)"
+		"IsEventHandler<> should accept a class with HandleEvent(SDL_Event)"
-	);
-	static_assert(
-		!IsEventHandler<EventHandlerOperator, SDL_Event>::value,
-		"IsEventHandler<> shouldn't accept a class with operator(const SDL_Event &)"
 	);
 	static_assert(
 		!IsEventHandler<InvalidEventHandler, SDL_Event>::value,
-		"IsEventHandler<> shouldn't accept a class with a different HandleEvent() signature"
+		"IsEventHandler<> shouldn't accept a class without a valid signature"
 	);
 }