Lua: Add support for default arguments

Former-commit-id: a319bcadf39b7e1633aaa23f360059a1f7449590

include/Nazara/Lua/LuaClass.hpp

@@ -42,12 +42,13 @@ namespace Nz
 			void SetFinalizer(FinalizerFunc finalizer);
 			void SetGetter(ClassIndexFunc getter);
 			void SetMethod(const String& name, ClassFunc method);
-			template<typename R, typename P, typename... Args> std::enable_if_t<std::is_base_of<P, T>::value> SetMethod(const String& name, R(P::*func)(Args...));
+			template<typename R, typename P, typename... Args, typename... DefArgs> std::enable_if_t<std::is_base_of<P, T>::value> SetMethod(const String& name, R(P::*func)(Args...), DefArgs... defArgs);
-			template<typename R, typename P, typename... Args> std::enable_if_t<std::is_base_of<P, T>::value> SetMethod(const String& name, R(P::*func)(Args...) const);
+			template<typename R, typename P, typename... Args, typename... DefArgs> std::enable_if_t<std::is_base_of<P, T>::value> SetMethod(const String& name, R(P::*func)(Args...) const, DefArgs... defArgs);
+			void SetBindMode(LuaBindMode mode);
 			void SetSetter(ClassIndexFunc setter);
 			void SetStaticGetter(StaticIndexFunc getter);
 			void SetStaticMethod(const String& name, StaticFunc func);
-			template<typename R, typename... Args> void SetStaticMethod(const String& name, R(*func)(Args...));
+			template<typename R, typename... Args, typename... DefArgs> void SetStaticMethod(const String& name, R(*func)(Args...), DefArgs... defArgs);
 			void SetStaticSetter(StaticIndexFunc getter);
 
 		private:

include/Nazara/Lua/LuaClass.inl

@@ -176,12 +176,12 @@ namespace Nz
 	}
 	
 	template<class T>
-	template<typename R, typename P, typename... Args>
+	template<typename R, typename P, typename... Args, typename... DefArgs>
-	std::enable_if_t<std::is_base_of<P, T>::value> LuaClass<T>::SetMethod(const String& name, R(P::*func)(Args...))
+	std::enable_if_t<std::is_base_of<P, T>::value> LuaClass<T>::SetMethod(const String& name, R(P::*func)(Args...), DefArgs... defArgs)
 	{
-		SetMethod(name, [func] (LuaInstance& instance, T& object) -> int
+		SetMethod(name, [func, defArgs...] (LuaInstance& instance, T& object) -> int
 		{
-			LuaImplMethodProxy<T, Args...> handler(instance, object);
+			LuaImplMethodProxy<T, Args...>::Impl<DefArgs...> handler(instance, object, defArgs...);
 			handler.ProcessArgs();
 
 			return handler.Invoke(func);
@@ -189,12 +189,12 @@ namespace Nz
 	}
 
 	template<class T>
-	template<typename R, typename P, typename... Args>
+	template<typename R, typename P, typename... Args, typename... DefArgs>
-	std::enable_if_t<std::is_base_of<P, T>::value> LuaClass<T>::SetMethod(const String& name, R(P::*func)(Args...) const)
+	std::enable_if_t<std::is_base_of<P, T>::value> LuaClass<T>::SetMethod(const String& name, R(P::*func)(Args...) const, DefArgs... defArgs)
 	{
-		SetMethod(name, [func] (LuaInstance& instance, T& object) -> int
+		SetMethod(name, [func, defArgs...] (LuaInstance& instance, T& object) -> int
 		{
-			LuaImplMethodProxy<T, Args...> handler(instance, object);
+			LuaImplMethodProxy<T, Args...>::Impl<DefArgs...> handler(instance, object, defArgs...);
 			handler.ProcessArgs();
 
 			return handler.Invoke(func);
@@ -220,12 +220,12 @@ namespace Nz
 	}
 
 	template<class T>
-	template<typename R, typename... Args>
+	template<typename R, typename... Args, typename... DefArgs>
-	void LuaClass<T>::SetStaticMethod(const String& name, R(*func)(Args...))
+	void LuaClass<T>::SetStaticMethod(const String& name, R(*func)(Args...), DefArgs... defArgs)
 	{
-		SetStaticMethod(name, [func] (LuaInstance& instance) -> int
+		SetStaticMethod(name, [func, defArgs...] (LuaInstance& instance) -> int
 		{
-			LuaImplFunctionProxy<Args...> handler(instance);
+			LuaImplFunctionProxy<Args...>::Impl<DefArgs...> handler(instance);
 			handler.ProcessArgs();
 
 			return handler.Invoke(func);

include/Nazara/Lua/LuaInstance.hpp

@@ -43,6 +43,7 @@ namespace Nz
 			bool Call(unsigned int argCount, unsigned int resultCount);
 
 			template<typename T> T Check(int index);
+			template<typename T> T Check(int index, T defValue);
 			void CheckAny(int index) const;
 			bool CheckBoolean(int index) const;
 			bool CheckBoolean(int index, bool defValue) const;
@@ -115,7 +116,7 @@ namespace Nz
 			void PushBoolean(bool value);
 			void PushCFunction(LuaCFunction func, unsigned int upvalueCount = 0);
 			void PushFunction(LuaFunction func);
-			template<typename R, typename... Args> void PushFunction(R(*func)(Args...));
+			template<typename R, typename... Args, typename... DefArgs> void PushFunction(R(*func)(Args...), DefArgs... defArgs);
 			void PushInteger(long long value);
 			void PushLightUserdata(void* value);
 			void PushMetatable(const char* str);

include/Nazara/Lua/LuaInstance.inl

@@ -4,6 +4,7 @@
 
 #include <Nazara/Core/Algorithm.hpp>
 #include <string>
+#include <type_traits>
 
 namespace Nz
 {
@@ -13,32 +14,68 @@ namespace Nz
 		return instance.CheckBoolean(index);
 	}
 
+	inline bool LuaImplQueryArg(LuaInstance& instance, unsigned int index, bool defValue, TypeTag<bool>)
+	{
+		return instance.CheckBoolean(index, defValue);
+	}
+
 	inline double LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<double>)
 	{
 		return instance.CheckNumber(index);
 	}
 
+	inline double LuaImplQueryArg(LuaInstance& instance, unsigned int index, double defValue, TypeTag<double>)
+	{
+		return instance.CheckNumber(index, defValue);
+	}
+
 	inline float LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<float>)
 	{
 		return static_cast<float>(instance.CheckNumber(index));
 	}
 
+	inline float LuaImplQueryArg(LuaInstance& instance, unsigned int index, float defValue, TypeTag<float>)
+	{
+		return static_cast<float>(instance.CheckNumber(index, defValue));
+	}
+
 	template<typename T>
 	std::enable_if_t<std::is_enum<T>::value, T> LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<T>)
 	{
 		return static_cast<T>(LuaImplQueryArg(instance, index, TypeTag<typename std::underlying_type<T>::type>()));
 	}
 
+	template<typename T>
+	std::enable_if_t<std::is_enum<T>::value, T> LuaImplQueryArg(LuaInstance& instance, unsigned int index, T defValue, TypeTag<T>)
+	{
+		using UnderlyingT = std::underlying_type_t<T>;
+		return static_cast<T>(LuaImplQueryArg(instance, index, static_cast<UnderlyingT>(defValue), TypeTag<UnderlyingT>()));
+	}
+
 	template<typename T>
 	std::enable_if_t<std::is_integral<T>::value && !std::is_unsigned<T>::value, T> LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<T>)
 	{
 		return static_cast<T>(instance.CheckInteger(index));
 	}
 
+	template<typename T>
+	std::enable_if_t<std::is_integral<T>::value && !std::is_unsigned<T>::value, T> LuaImplQueryArg(LuaInstance& instance, unsigned int index, T defValue, TypeTag<T>)
+	{
+		return static_cast<T>(instance.CheckInteger(index, defValue));
+	}
+
 	template<typename T>
 	std::enable_if_t<std::is_unsigned<T>::value, T> LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<T>)
 	{
-		return static_cast<T>(LuaImplQueryArg(instance, index, TypeTag<typename std::make_signed<T>::type>()));
+		using SignedT = std::make_signed_t<T>;
+		return static_cast<T>(LuaImplQueryArg(instance, index, TypeTag<SignedT>()));
+	}
+
+	template<typename T>
+	std::enable_if_t<std::is_unsigned<T>::value, T> LuaImplQueryArg(LuaInstance& instance, unsigned int index, T defValue, TypeTag<T>)
+	{
+		using SignedT = std::make_signed_t<T>;
+		return static_cast<T>(LuaImplQueryArg(instance, index, static_cast<SignedT>(defValue), TypeTag<SignedT>()));
 	}
 
 	inline std::string LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<std::string>)
@@ -49,6 +86,14 @@ namespace Nz
 		return std::string(str, strLength);
 	}
 
+	inline std::string LuaImplQueryArg(LuaInstance& instance, unsigned int index, const std::string& defValue, TypeTag<std::string>)
+	{
+		std::size_t strLength = 0;
+		const char* str = instance.CheckString(index, defValue.c_str(), &strLength);
+
+		return std::string(str, strLength);
+	}
+
 	inline String LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<String>)
 	{
 		std::size_t strLength = 0;
@@ -57,12 +102,35 @@ namespace Nz
 		return String(str, strLength);
 	}
 
+	inline String LuaImplQueryArg(LuaInstance& instance, unsigned int index, const String& defValue, TypeTag<String>)
+	{
+		std::size_t strLength = 0;
+		const char* str = instance.CheckString(index, defValue.GetConstBuffer(), &strLength);
+
+		return String(str, strLength);
+	}
+
 	template<typename T>
 	T LuaImplQueryArg(LuaInstance& instance, unsigned int index, TypeTag<const T&>)
 	{
 		return LuaImplQueryArg(instance, index, TypeTag<T>());
 	}
 
+	template<typename T>
+	T LuaImplQueryArg(LuaInstance& instance, unsigned int index, const T& defValue, TypeTag<T> tag)
+	{
+		if (instance.IsValid(index))
+			return LuaImplQueryArg(instance, index, tag);
+		else
+			return defValue;
+	}
+
+	template<typename T>
+	T LuaImplQueryArg(LuaInstance& instance, unsigned int index, const T& defValue, TypeTag<const T&>)
+	{
+		return LuaImplQueryArg(instance, index, defValue, TypeTag<T>());
+	}
+
 	// Function returns
 	inline int LuaImplReplyVal(LuaInstance& instance, bool val, TypeTag<bool>)
 	{
@@ -128,32 +196,50 @@ namespace Nz
 		return retVal;
 	}
 
+	template<typename hasDefault>
+	struct LuaImplArgProcesser;
+
+	template<>
+	struct LuaImplArgProcesser<std::true_type>
+	{
+		template<std::size_t N, std::size_t FirstDefArg, typename ArgType, typename ArgContainer, typename DefArgContainer>
+		static void Process(LuaInstance& instance, ArgContainer& args, DefArgContainer& defArgs)
+		{
+			std::get<N>(args) = std::move(LuaImplQueryArg(instance, N + 1, std::get<N - FirstDefArg>(defArgs), TypeTag<ArgType>()));
+		}
+	};
+
+	template<>
+	struct LuaImplArgProcesser<std::false_type>
+	{
+		template<std::size_t N, std::size_t FirstDefArg, typename ArgType, typename ArgContainer, typename DefArgContainer>
+		static void Process(LuaInstance& instance, ArgContainer& args, DefArgContainer& defArgs)
+		{
+			NazaraUnused(defArgs);
+
+			std::get<N>(args) = std::move(LuaImplQueryArg(instance, N + 1, TypeTag<ArgType>()));
+		}
+	};
+
 	template<typename... Args>
 	class LuaImplFunctionProxy
 	{
 		public:
-			LuaImplFunctionProxy(LuaInstance& instance) :
+			template<typename... DefArgs>
-			m_instance(instance)
+			class Impl
 			{
-			}
+				static constexpr std::size_t ArgCount = sizeof...(Args);
+				static constexpr std::size_t DefArgCount = sizeof...(DefArgs);
 
-			template<unsigned int N>
+				static_assert(ArgCount >= DefArgCount, "There cannot be more default arguments than argument");
-			void ProcessArgs()
-			{
-				// No argument to process
-			}
 
-			template<unsigned int N, typename ArgType>
+				static constexpr std::size_t FirstDefArg = ArgCount - DefArgCount;
-			void ProcessArgs()
-			{
-				std::get<N>(m_args) = std::move(LuaImplQueryArg(m_instance, N+1, TypeTag<ArgType>()));
-			}
 
-			template<int N, typename ArgType1, typename ArgType2, typename... Rest>
+				public:
-			void ProcessArgs()
+					Impl(LuaInstance& instance, DefArgs... defArgs) :
+					m_defaultArgs(std::forward<DefArgs>(defArgs)...),
+					m_instance(instance),
 					{
-				ProcessArgs<N, ArgType1>();
-				ProcessArgs<N+1, ArgType2, Rest...>();
 					}
 
 					void ProcessArgs()
@@ -174,39 +260,57 @@ namespace Nz
 					}
 
 				private:
-			std::tuple<std::remove_cv_t<std::remove_reference_t<Args>>...> m_args;
+					using ArgContainer = std::tuple<std::remove_cv_t<std::remove_reference_t<Args>>...>;
+					using DefArgContainer = std::tuple<std::remove_cv_t<std::remove_reference_t<DefArgs>>...>;
+
+					template<std::size_t N>
+					void ProcessArgs()
+					{
+						// No argument to process
+					}
+
+					template<std::size_t N, typename ArgType>
+					void ProcessArgs()
+					{
+						using CheckDefValue = typename std::integral_constant<bool, N >= FirstDefArg>;
+						LuaImplArgProcesser<CheckDefValue>::Process<N, FirstDefArg, ArgType>(m_instance, m_args, m_defaultArgs);
+					}
+
+					template<std::size_t N, typename ArgType1, typename ArgType2, typename... Rest>
+					void ProcessArgs()
+					{
+						ProcessArgs<N, ArgType1>();
+						ProcessArgs<N + 1, ArgType2, Rest...>();
+					}
+
+					ArgContainer m_args;
+					DefArgContainer m_defaultArgs;
 					LuaInstance& m_instance;
 			};
+	};
 
 	template<typename T, typename... Args>
 	class LuaImplMethodProxy
 	{
 		public:
-			LuaImplMethodProxy(LuaInstance& instance, T& object) :
+			template<typename... DefArgs>
+			class Impl
+			{
+				static constexpr std::size_t ArgCount = sizeof...(Args);
+				static constexpr std::size_t DefArgCount = sizeof...(DefArgs);
+
+				static_assert(ArgCount >= DefArgCount, "There cannot be more default arguments than argument");
+
+				static constexpr std::size_t FirstDefArg = ArgCount - DefArgCount;
+
+				public:
+					Impl(LuaInstance& instance, T& object, DefArgs... defArgs) :
+					m_defaultArgs(std::forward<DefArgs>(defArgs)...),
 					m_instance(instance),
 					m_object(object)
 					{
 					}
 
-			template<unsigned int N>
-			void ProcessArgs()
-			{
-				// No argument to process
-			}
-
-			template<unsigned int N, typename ArgType>
-			void ProcessArgs()
-			{
-				std::get<N>(m_args) = std::move(LuaImplQueryArg(m_instance, N + 1, TypeTag<ArgType>()));
-			}
-
-			template<unsigned int N, typename ArgType1, typename ArgType2, typename... Rest>
-			void ProcessArgs()
-			{
-				ProcessArgs<N, ArgType1>();
-				ProcessArgs<N + 1, ArgType2, Rest...>();
-			}
-
 					void ProcessArgs()
 					{
 						ProcessArgs<0, Args...>();
@@ -239,10 +343,35 @@ namespace Nz
 					}
 
 				private:
-			std::tuple<std::remove_cv_t<std::remove_reference_t<Args>>...> m_args;
+					using ArgContainer = std::tuple<std::remove_cv_t<std::remove_reference_t<Args>>...>;
+					using DefArgContainer = std::tuple<std::remove_cv_t<std::remove_reference_t<DefArgs>>...>;
+
+					template<std::size_t N>
+					void ProcessArgs()
+					{
+						// No argument to process
+					}
+
+					template<std::size_t N, typename ArgType>
+					void ProcessArgs()
+					{
+						using CheckDefValue = typename std::integral_constant<bool, N >= FirstDefArg>;
+						LuaImplArgProcesser<CheckDefValue>::Process<N, FirstDefArg, ArgType>(m_instance, m_args, m_defaultArgs);
+					}
+
+					template<std::size_t N, typename ArgType1, typename ArgType2, typename... Rest>
+					void ProcessArgs()
+					{
+						ProcessArgs<N, ArgType1>();
+						ProcessArgs<N + 1, ArgType2, Rest...>();
+					}
+
+					ArgContainer m_args;
+					DefArgContainer m_defaultArgs;
 					LuaInstance& m_instance;
 					T& m_object;
 			};
+	};
 
 	template<typename T>
 	T LuaInstance::Check(int index)
@@ -250,18 +379,24 @@ namespace Nz
 		return LuaImplQueryArg(*this, index, TypeTag<T>());
 	}
 
+	template<typename T>
+	T LuaInstance::Check(int index, T defValue)
+	{
+		return LuaImplQueryArg(*this, index, defValue, TypeTag<T>());
+	}
+
 	template<typename T>
 	int LuaInstance::Push(T arg)
 	{
 		return LuaImplReplyVal(*this, std::move(arg), TypeTag<T>());
 	}
 
-	template<typename R, typename... Args>
+	template<typename R, typename... Args, typename... DefArgs>
-	void LuaInstance::PushFunction(R (*func)(Args...))
+	void LuaInstance::PushFunction(R (*func)(Args...), DefArgs... defArgs)
 	{
-		PushFunction([func](LuaInstance& instance) -> int
+		PushFunction([func, defArgs...](LuaInstance& instance) -> int
 		{
-			LuaImplFunctionProxy<Args...> handler(instance);
+			LuaImplFunctionProxy<Args...>::Impl<DefArgs...> handler(instance);
 			handler.ProcessArgs();
 
 			return handler.Invoke(func);