From bb72714216cbdf5a301e2b38dba81b14a616f0f4 Mon Sep 17 00:00:00 2001
From: TimePath <andrew.hardaker1995@gmail.com>
Date: Sun, 31 Dec 2017 16:58:54 +1100
Subject: [PATCH] Embrace variadic templates

---
 contrib/meshtex/MeshEntity.h |   4 +-
 libs/generic/callback.h      | 524 +++++++++++------------------------
 libs/generic/functional.h    | 476 +++++++++++++------------------
 libs/signal/isignal.h        | 197 ++++++-------
 libs/signal/signal.h         |   6 +-
 libs/stringio.h              |  16 +-
 radiant/csg.cpp              |  18 +-
 radiant/dialog.h             |   4 +-
 radiant/renderstate.cpp      |   4 +-
 radiant/selection.cpp        |   2 +-
 radiant/texwindow.cpp        |   2 +-
 11 files changed, 456 insertions(+), 797 deletions(-)

diff --git a/contrib/meshtex/MeshEntity.h b/contrib/meshtex/MeshEntity.h
index ad351b41..5f26e56f 100644
--- a/contrib/meshtex/MeshEntity.h
+++ b/contrib/meshtex/MeshEntity.h
@@ -119,7 +119,7 @@ public: // public types
     */
    template<typename ObjectClass, void (ObjectClass::*member)(float, float)>
    class TexInfoCallbackMethod :
-      public BindFirstOpaque2<Member2<ObjectClass, float, float, void, member> >
+      public BindFirstOpaque<Member2<ObjectClass, float, float, void, member> >
    {
    public:
       /**
@@ -128,7 +128,7 @@ public: // public types
        * @param object The object on which to invoke the callback method.
        */
       TexInfoCallbackMethod(ObjectClass& object) :
-         BindFirstOpaque2<Member2<ObjectClass, float, float, void, member> >(object) {}
+         BindFirstOpaque<Member2<ObjectClass, float, float, void, member> >(object) {}
    };
 
 public: // public methods
diff --git a/libs/generic/callback.h b/libs/generic/callback.h
index 1b50634d..4b35f719 100644
--- a/libs/generic/callback.h
+++ b/libs/generic/callback.h
@@ -88,131 +88,6 @@ public:
 	}
 };
 
-template<typename Caller>
-class BindFirstOpaque
-{
-	typedef typename Caller::first_argument_type FirstBound;
-	FirstBound firstBound;
-public:
-	typedef typename Caller::result_type result_type;
-	explicit BindFirstOpaque( FirstBound firstBound ) : firstBound( firstBound ){
-	}
-	result_type operator()() const {
-		return Caller::call( firstBound );
-	}
-	FirstBound getBound() const {
-		return firstBound;
-	}
-	static result_type thunk( void* environment ){
-		return Caller::call( ConvertFromOpaque<FirstBound>::apply( environment ) );
-	}
-	void* getEnvironment() const {
-		return convertToOpaque( firstBound );
-	}
-};
-
-template<typename Caller>
-class BindFirstOpaque1
-{
-	typedef typename Caller::first_argument_type FirstBound;
-	FirstBound firstBound;
-public:
-	typedef typename Caller::second_argument_type first_argument_type;
-	typedef typename Caller::result_type result_type;
-	explicit BindFirstOpaque1( FirstBound firstBound ) : firstBound( firstBound ){
-	}
-	result_type operator()( first_argument_type a1 ) const {
-		return Caller::call( firstBound, a1 );
-	}
-	FirstBound getBound() const {
-		return firstBound;
-	}
-	static result_type thunk( void* environment, first_argument_type a1 ){
-		return Caller::call( ConvertFromOpaque<FirstBound>::apply( environment ), a1 );
-	}
-	void* getEnvironment() const {
-		return convertToOpaque( firstBound );
-	}
-};
-
-template<typename Caller>
-class BindFirstOpaque2
-{
-	typedef typename Caller::first_argument_type FirstBound;
-	FirstBound firstBound;
-public:
-	typedef typename Caller::second_argument_type first_argument_type;
-	typedef typename Caller::third_argument_type second_argument_type;
-	typedef typename Caller::result_type result_type;
-	explicit BindFirstOpaque2( FirstBound firstBound ) : firstBound( firstBound ){
-	}
-	result_type operator()( first_argument_type a1, second_argument_type a2 ) const {
-		return Caller::call( firstBound, a1, a2 );
-	}
-	FirstBound getBound() const {
-		return firstBound;
-	}
-	static result_type thunk( void* environment, first_argument_type a1, second_argument_type a2 ){
-		return Caller::call( ConvertFromOpaque<FirstBound>::apply( environment ), a1, a2 );
-	}
-	void* getEnvironment() const {
-		return convertToOpaque( firstBound );
-	}
-};
-
-template<typename Caller>
-class BindFirstOpaque3
-{
-	typedef typename Caller::first_argument_type FirstBound;
-	FirstBound firstBound;
-public:
-	typedef typename Caller::second_argument_type first_argument_type;
-	typedef typename Caller::third_argument_type second_argument_type;
-	typedef typename Caller::fourth_argument_type third_argument_type;
-	typedef typename Caller::result_type result_type;
-	explicit BindFirstOpaque3( FirstBound firstBound ) : firstBound( firstBound ){
-	}
-	result_type operator()( first_argument_type a1, second_argument_type a2, third_argument_type a3 ) const {
-		return Caller::call( firstBound, a1, a2, a3 );
-	}
-	FirstBound getBound() const {
-		return firstBound;
-	}
-	static result_type thunk( void* environment, first_argument_type a1, second_argument_type a2, third_argument_type a3 ){
-		return Caller::call( ConvertFromOpaque<FirstBound>::apply( environment ), a1, a2, a3 );
-	}
-	void* getEnvironment() const {
-		return convertToOpaque( firstBound );
-	}
-};
-
-template<typename Caller>
-class BindFirstOpaque4
-{
-	typedef typename Caller::first_argument_type FirstBound;
-	FirstBound firstBound;
-public:
-	typedef typename Caller::second_argument_type first_argument_type;
-	typedef typename Caller::third_argument_type second_argument_type;
-	typedef typename Caller::fourth_argument_type third_argument_type;
-	typedef typename Caller::fifth_argument_type fourth_argument_type;
-	typedef typename Caller::result_type result_type;
-	explicit BindFirstOpaque4( FirstBound firstBound ) : firstBound( firstBound ){
-	}
-	result_type operator()( first_argument_type a1, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ) const {
-		return Caller::call( firstBound, a1, a2, a3, a4 );
-	}
-	FirstBound getBound() const {
-		return firstBound;
-	}
-	static result_type thunk( void* environment, first_argument_type a1, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ){
-		return Caller::call( ConvertFromOpaque<FirstBound>::apply( environment ), a1, a2, a3, a4 );
-	}
-	void* getEnvironment() const {
-		return convertToOpaque( firstBound );
-	}
-};
-
 template<typename Thunk_>
 class CallbackBase
 {
@@ -244,38 +119,82 @@ inline bool operator<( const CallbackBase<Thunk>& self, const CallbackBase<Thunk
 	       ( !( other.getEnvironment() < self.getEnvironment() ) && self.getThunk() < other.getThunk() );
 }
 
+template<class Caller, class F>
+class BindFirstOpaqueN;
+
+template<class Caller, class R, class FirstBound, class... Ts>
+class BindFirstOpaqueN<Caller, R(FirstBound, Ts...)>
+{
+	FirstBound firstBound;
+public:
+	explicit BindFirstOpaqueN( FirstBound firstBound ) : firstBound( firstBound ){
+	}
+
+	R operator()( Ts... args ) const {
+		return Caller::call( firstBound, args... );
+	}
+
+	FirstBound getBound() const {
+		return firstBound;
+	}
+
+	static R thunk( void *environment, Ts... args ){
+		return Caller::call( ConvertFromOpaque<FirstBound>::apply( environment ), args... );
+	}
+
+	void *getEnvironment() const {
+		return convertToOpaque( firstBound );
+	}
+};
+
+template<class Caller>
+using BindFirstOpaque = BindFirstOpaqueN<Caller, typename Caller::func>;
+
+template<class F>
+class CallbackN;
+
+template<class R, class... Ts>
+class CallbackN<R(Ts...)> : public CallbackBase<R(*)(void *, Ts...)>
+{
+	using Base = CallbackBase<R (*)(void *, Ts...)>;
+
+	static R nullThunk( void *, Ts... ){
+	}
+
+public:
+	using func = R(Ts...);
+
+	CallbackN() : Base( 0, nullThunk ){
+	}
+
+	template<typename Caller>
+	CallbackN( const BindFirstOpaque<Caller>& caller ) : Base( caller.getEnvironment(), BindFirstOpaque<Caller>::thunk ){
+	}
+
+	CallbackN( void *environment, typename Base::Thunk function ) : Base( environment, function ){
+	}
+
+	R operator()( Ts... args ) const {
+		return Base::getThunk()( Base::getEnvironment(), args... );
+	}
+};
 
 /// \brief Combines a void pointer with a pointer to a function which operates on a void pointer.
 ///
 /// Use with the callback constructors MemberCaller, ConstMemberCaller, ReferenceCaller, ConstReferenceCaller, PointerCaller, ConstPointerCaller and FreeCaller.
-template<typename Result>
-class Callback0 : public CallbackBase<Result ( * )( void* )>
+template<class Result>
+class Callback0 : public CallbackN<Result()>
 {
-	typedef CallbackBase<Result ( * )( void* )> Base;
-	static Result nullThunk( void* ){
-	}
-
 public:
-	typedef Result result_type;
-
-	Callback0() : Base( 0, nullThunk ){
-	}
-	template<typename Caller>
-	Callback0( const BindFirstOpaque<Caller>& caller ) : Base( caller.getEnvironment(), BindFirstOpaque<Caller>::thunk ){
-	}
-	Callback0( void* environment, typename Base::Thunk function ) : Base( environment, function ){
-	}
-	result_type operator()() const {
-		return Base::getThunk() ( Base::getEnvironment() );
-	}
+	using CallbackN<Result()>::CallbackN;
 };
 
 template<typename Caller>
-inline Callback0<typename Caller::result_type> makeCallback0( const Caller& caller, typename Caller::first_argument_type callee ){
-	return Callback0<typename Caller::result_type>( BindFirstOpaque<Caller>( callee ) );
+inline Callback0<get_result_type<Caller>> makeCallback0( const Caller& caller, get_argument<Caller, 0> callee ){
+	return Callback0<get_result_type<Caller>>( BindFirstOpaque<Caller>( callee ) );
 }
 template<typename Caller>
-inline Callback0<typename Caller::result_type> makeStatelessCallback0( const Caller& caller ){
+inline Callback0<get_result_type<Caller>> makeStatelessCallback0( const Caller& caller ){
 	return makeCallback0( Caller0To1<Caller>(), 0 );
 }
 
@@ -286,35 +205,20 @@ typedef Callback0<void> Callback;
 /// \brief Combines a void pointer with a pointer to a function which operates on a void pointer and one other argument.
 ///
 /// Use with the callback constructors MemberCaller1, ConstMemberCaller1, ReferenceCaller1, ConstReferenceCaller1, PointerCaller1, ConstPointerCaller1 and FreeCaller1.
-template<typename FirstArgument, typename Result>
-class Callback1 : public CallbackBase<Result ( * )( void*, FirstArgument )>
+template<class FirstArgument, class Result>
+class Callback1 : public CallbackN<Result(FirstArgument)>
 {
-	typedef CallbackBase<Result ( * )( void*, FirstArgument )> Base;
-	static Result nullThunk( void*, FirstArgument ){
-	}
-
 public:
-	typedef FirstArgument first_argument_type;
-	typedef Result result_type;
-
-	Callback1() : Base( 0, nullThunk ){
-	}
-	template<typename Caller>
-	Callback1( const BindFirstOpaque1<Caller>& caller ) : Base( caller.getEnvironment(), BindFirstOpaque1<Caller>::thunk ){
-	}
-	Callback1( void* environment, typename Base::Thunk function ) : Base( environment, function ){
-	}
-	result_type operator()( FirstArgument firstArgument ) const {
-		return Base::getThunk() ( Base::getEnvironment(), firstArgument );
-	}
+	using CallbackN<Result(FirstArgument)>::CallbackN;
 };
 
 template<typename Caller>
-inline Callback1<typename Caller::second_argument_type, typename Caller::result_type> makeCallback1( const Caller& caller, typename Caller::first_argument_type callee ){
-	return Callback1<typename Caller::second_argument_type, typename Caller::result_type>( BindFirstOpaque1<Caller>( callee ) );
+inline Callback1<get_argument<Caller, 1>, get_result_type<Caller>>
+makeCallback1( const Caller& caller, get_argument<Caller, 0> callee ){
+	return Callback1<get_argument<Caller, 1>, get_result_type<Caller>>( BindFirstOpaque<Caller>( callee ) );
 }
 template<typename Caller>
-inline Callback1<typename Caller::second_argument_type, typename Caller::result_type> makeStatelessCallback1( const Caller& caller ){
+inline Callback1<get_argument<Caller, 1>, get_result_type<Caller>> makeStatelessCallback1( const Caller& caller ){
 	return makeCallback1( Caller1To2<Caller>(), 0 );
 }
 
@@ -322,47 +226,30 @@ inline Callback1<typename Caller::second_argument_type, typename Caller::result_
 /// \brief Combines a void pointer with a pointer to a function which operates on a void pointer and two other arguments.
 ///
 template<typename FirstArgument, typename SecondArgument, typename Result>
-class Callback2 : public CallbackBase<Result ( * )( void*, FirstArgument, SecondArgument )>
+class Callback2 : public CallbackN<Result(FirstArgument, SecondArgument)>
 {
-	typedef CallbackBase<Result ( * )( void*, FirstArgument, SecondArgument )> Base;
-	static Result nullThunk( void*, FirstArgument, SecondArgument ){
-	}
-
 public:
-	typedef FirstArgument first_argument_type;
-	typedef SecondArgument second_argument_type;
-	typedef Result result_type;
-
-	Callback2() : Base( 0, nullThunk ){
-	}
-	template<typename Caller>
-	Callback2( const BindFirstOpaque2<Caller>& caller ) : Base( caller.getEnvironment(), BindFirstOpaque2<Caller>::thunk ){
-	}
-	Callback2( void* environment, typename Base::Thunk function ) : Base( environment, function ){
-	}
-	result_type operator()( FirstArgument firstArgument, SecondArgument secondArgument ) const {
-		return Base::getThunk() ( Base::getEnvironment(), firstArgument, secondArgument );
-	}
+	using CallbackN<Result(FirstArgument, SecondArgument)>::CallbackN;
 };
 
 template<typename Caller>
 inline Callback2<
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::result_type
-> makeCallback2( const Caller& caller, typename Caller::first_argument_type callee ){
+         get_argument<Caller, 1>,
+         get_argument<Caller, 2>,
+         get_result_type<Caller>
+> makeCallback2( const Caller& caller, get_argument<Caller, 0> callee ){
 	return Callback2<
-	           typename Caller::second_argument_type,
-	           typename Caller::third_argument_type,
-	           typename Caller::result_type
-	       >( BindFirstOpaque2<Caller>( callee ) );
+	           get_argument<Caller, 1>,
+	           get_argument<Caller, 2>,
+	           get_result_type<Caller>
+	       >( BindFirstOpaque<Caller>( callee ) );
 }
 template<typename Caller>
 inline Callback2<
-         typename Caller::first_argument_type,
-         typename Caller::second_argument_type,
-         typename Caller::result_type
-> makeStatelessCallback2( const Caller& caller ){
+         get_argument<Caller, 0>,
+         get_argument<Caller, 1>,
+         get_result_type<Caller>
+> makeStatelessCallback2( const Caller& caller){
 	return makeCallback2( Caller2To3<Caller>(), 0 );
 }
 
@@ -370,50 +257,32 @@ inline Callback2<
 /// \brief Combines a void pointer with a pointer to a function which operates on a void pointer and three other arguments.
 ///
 template<typename FirstArgument, typename SecondArgument, typename ThirdArgument, typename Result>
-class Callback3 : public CallbackBase<Result ( * )( void*, FirstArgument, SecondArgument, ThirdArgument )>
+class Callback3 : public CallbackN<Result(FirstArgument, SecondArgument, ThirdArgument)>
 {
-	typedef CallbackBase<Result ( * )( void*, FirstArgument, SecondArgument, ThirdArgument )> Base;
-	static Result nullThunk( void*, FirstArgument, SecondArgument, ThirdArgument ){
-	}
-
 public:
-	typedef FirstArgument first_argument_type;
-	typedef SecondArgument second_argument_type;
-	typedef ThirdArgument third_argument_type;
-	typedef Result result_type;
-
-	Callback3() : Base( 0, nullThunk ){
-	}
-	template<typename Caller>
-	Callback3( const BindFirstOpaque3<Caller>& caller ) : Base( caller.getEnvironment(), BindFirstOpaque3<Caller>::thunk ){
-	}
-	Callback3( void* environment, typename Base::Thunk function ) : Base( environment, function ){
-	}
-	result_type operator()( FirstArgument firstArgument, SecondArgument secondArgument, ThirdArgument thirdArgument ) const {
-		return Base::getThunk() ( Base::getEnvironment(), firstArgument, secondArgument, thirdArgument );
-	}
+	using CallbackN<Result(FirstArgument, SecondArgument, ThirdArgument)>::CallbackN;
 };
 
 template<typename Caller>
 inline Callback3<
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::fourth_argument_type,
-         typename Caller::result_type
-> makeCallback3( const Caller& caller, typename Caller::first_argument_type callee ){
+         get_argument<Caller, 1>,
+         get_argument<Caller, 2>,
+         get_argument<Caller, 3>,
+         get_result_type<Caller>
+> makeCallback3( const Caller& caller, get_argument<Caller, 0> callee ){
 	return Callback3<
-	            typename Caller::second_argument_type,
-	            typename Caller::third_argument_type,
-	            typename Caller::fourth_argument_type,
-	            typename Caller::result_type
-	       >( BindFirstOpaque3<Caller>( callee ) );
+	            get_argument<Caller, 1>,
+	            get_argument<Caller, 2>,
+	            get_argument<Caller, 3>,
+	            get_result_type<Caller>
+	       >( BindFirstOpaque<Caller>( callee ) );
 }
 template<typename Caller>
 inline Callback3<
-         typename Caller::first_argument_type,
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::result_type
+         get_argument<Caller, 0>,
+         get_argument<Caller, 1>,
+         get_argument<Caller, 2>,
+         get_result_type<Caller>
 > makeStatelessCallback3( const Caller& caller ){
 	return makeCallback3( Caller3To4<Caller>(), 0 );
 }
@@ -422,54 +291,35 @@ inline Callback3<
 /// \brief Combines a void pointer with a pointer to a function which operates on a void pointer and four other arguments.
 ///
 template<typename FirstArgument, typename SecondArgument, typename ThirdArgument, typename FourthArgument, typename Result>
-class Callback4 : public CallbackBase<Result ( * )( void*, FirstArgument, SecondArgument, ThirdArgument, FourthArgument )>
+class Callback4 : public CallbackN<Result(FirstArgument, SecondArgument, ThirdArgument, FourthArgument)>
 {
-	typedef CallbackBase<Result ( * )( void*, FirstArgument, SecondArgument, ThirdArgument, FourthArgument )> Base;
-	static Result nullThunk( void*, FirstArgument, SecondArgument, ThirdArgument, FourthArgument ){
-	}
-
 public:
-	typedef FirstArgument first_argument_type;
-	typedef SecondArgument second_argument_type;
-	typedef ThirdArgument third_argument_type;
-	typedef FourthArgument fourth_argument_type;
-	typedef Result result_type;
-
-	Callback4() : Base( 0, nullThunk ){
-	}
-	template<typename Caller>
-	Callback4( const BindFirstOpaque4<Caller>& caller ) : Base( caller.getEnvironment(), BindFirstOpaque4<Caller>::thunk ){
-	}
-	Callback4( void* environment, typename Base::Thunk function ) : Base( environment, function ){
-	}
-	result_type operator()( FirstArgument firstArgument, SecondArgument secondArgument, ThirdArgument thirdArgument, FourthArgument fourthArgument ) const {
-		return Base::getThunk() ( Base::getEnvironment(), firstArgument, secondArgument, thirdArgument, fourthArgument );
-	}
+	using CallbackN<Result(FirstArgument, SecondArgument, ThirdArgument, FourthArgument)>::CallbackN;
 };
 
 template<typename Caller>
 inline Callback4<
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::fourth_argument_type,
-         typename Caller::fifth_argument_type,
-         typename Caller::result_type
-> makeCallback4( const Caller& caller, typename Caller::first_argument_type callee ){
+         get_argument<Caller, 1>,
+         get_argument<Caller, 2>,
+         get_argument<Caller, 3>,
+         get_argument<Caller, 4>,
+         get_result_type<Caller>
+> makeCallback4( const Caller& caller, get_argument<Caller, 0> callee ){
 	return Callback4<
-	            typename Caller::second_argument_type,
-	            typename Caller::third_argument_type,
-	            typename Caller::fourth_argument_type,
-	            typename Caller::fifth_argument_type,
-	            typename Caller::result_type
-	       >( BindFirstOpaque4<Caller>( callee ) );
+	            get_argument<Caller, 1>,
+	            get_argument<Caller, 2>,
+	            get_argument<Caller, 3>,
+	            get_argument<Caller, 4>,
+	            get_result_type<Caller>
+	       >( BindFirstOpaque<Caller>( callee ) );
 }
 template<typename Caller>
 inline Callback4<
-         typename Caller::first_argument_type,
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::fourth_argument_type,
-         typename Caller::result_type
+         get_argument<Caller, 0>,
+         get_argument<Caller, 1>,
+         get_argument<Caller, 2>,
+         get_argument<Caller, 3>,
+         get_result_type<Caller>
 > makeStatelessCallback4( const Caller& caller ){
 	return makeCallback4( Caller4To5<Caller>(), 0 );
 }
@@ -480,140 +330,80 @@ inline Callback4<
 /// \dontinclude generic/callback.cpp
 /// \skipline MemberCaller example
 /// \until end example
-template<typename Environment, void( Environment::*member ) ( )>
-class MemberCaller : public BindFirstOpaque< Member<Environment, void, member> >
-{
-public:
-	MemberCaller( Environment& environment ) : BindFirstOpaque< Member<Environment, void, member> >( environment ){
-	}
-};
+template<class Environment, void(Environment::*member)()>
+using MemberCaller = BindFirstOpaque<Member<Environment, void, member>>;
 
 /// \brief Forms a Callback from a const Environment reference and a const Environment member-function.
 ///
 /// \dontinclude generic/callback.cpp
 /// \skipline MemberCaller example
 /// \until end example
-template<typename Environment, void( Environment::*member ) ( ) const>
-class ConstMemberCaller : public BindFirstOpaque< ConstMember<Environment, void, member> >
-{
-public:
-	ConstMemberCaller( const Environment& environment ) : BindFirstOpaque< ConstMember<Environment, void, member> >( environment ){
-	}
-};
+template<class Environment, void(Environment::*member)() const>
+using ConstMemberCaller = BindFirstOpaque<ConstMember<Environment, void, member>>;
 
 /// \brief Forms a Callback from a non-const Environment reference and a const Environment member-function which takes one argument.
-template<typename Environment, typename FirstArgument, void( Environment::*member ) (FirstArgument)>
-class MemberCaller1 : public BindFirstOpaque1< Member1<Environment, FirstArgument, void, member> >
-{
-public:
-	MemberCaller1( Environment& environment ) : BindFirstOpaque1< Member1<Environment, FirstArgument, void, member> >( environment ){
-	}
-};
+template<class Environment, class FirstArgument, void(Environment::*member)(FirstArgument)>
+using MemberCaller1 = BindFirstOpaque<Member1<Environment, FirstArgument, void, member>>;
 
 /// \brief Forms a Callback from a const Environment reference and a const Environment member-function which takes one argument.
-template<typename Environment, typename FirstArgument, void( Environment::*member ) (FirstArgument) const>
-class ConstMemberCaller1 : public BindFirstOpaque1< ConstMember1<Environment, FirstArgument, void, member> >
-{
-public:
-	ConstMemberCaller1( const Environment& environment ) : BindFirstOpaque1< ConstMember1<Environment, FirstArgument, void, member> >( environment ){
-	}
-};
+template<class Environment, class FirstArgument, void(Environment::*member)(FirstArgument) const>
+using ConstMemberCaller1 = BindFirstOpaque<ConstMember1<Environment, FirstArgument, void, member>>;
 
 /// \brief Forms a Callback from a non-const Environment reference and a free function which operates on a non-const Environment reference.
 ///
 /// \dontinclude generic/callback.cpp
 /// \skipline ReferenceCaller example
 /// \until end example
-template<typename Environment, void( *func ) (Environment&)>
-class ReferenceCaller : public BindFirstOpaque< Function1<Environment&, void, func> >
-{
-public:
-	ReferenceCaller( Environment& environment ) : BindFirstOpaque< Function1<Environment&, void, func> >( environment ){
-	}
-};
+template<class Environment, void(*func)(Environment &)>
+using ReferenceCaller = BindFirstOpaque<Function1<Environment &, void, func>>;
 
 /// \brief Forms a Callback from a const Environment reference and a free function which operates on a const Environment reference.
 ///
 /// \dontinclude generic/callback.cpp
 /// \skipline ReferenceCaller example
 /// \until end example
-template<typename Environment, void( *func ) (const Environment&)>
-class ConstReferenceCaller : public BindFirstOpaque< Function1<const Environment&, void, func> >
-{
-public:
-	ConstReferenceCaller( const Environment& environment ) : BindFirstOpaque< Function1<const Environment&, void, func> >( environment ){
-	}
-};
+template<class Environment, void(*func)(const Environment &)>
+using ConstReferenceCaller = BindFirstOpaque<Function1<const Environment &, void, func>>;
 
 /// \brief Forms a Callback from a non-const Environment reference and a free function which operates on a non-const Environment reference and one other argument.
-template<typename Environment, typename FirstArgument, void( *func ) ( Environment&, FirstArgument )>
-class ReferenceCaller1 : public BindFirstOpaque1< Function2<Environment&, FirstArgument, void, func> >
-{
-public:
-	ReferenceCaller1( Environment& environment ) : BindFirstOpaque1< Function2<Environment&, FirstArgument, void, func> >( environment ){
-	}
-};
+template<class Environment, class FirstArgument, void(*func)(Environment &, FirstArgument)>
+using ReferenceCaller1 = BindFirstOpaque<Function2<Environment &, FirstArgument, void, func>>;
 
 /// \brief Forms a Callback from a const Environment reference and a free function which operates on a const Environment reference and one other argument.
-template<typename Environment, typename FirstArgument, void( *func ) ( const Environment&, FirstArgument )>
-class ConstReferenceCaller1 : public BindFirstOpaque1< Function2<const Environment&, FirstArgument, void, func> >
-{
-public:
-	ConstReferenceCaller1( const Environment& environment ) : BindFirstOpaque1< Function2<const Environment&, FirstArgument, void, func> >( environment ){
-	}
-};
+template<class Environment, class FirstArgument, void(*func)(const Environment &, FirstArgument)>
+using ConstReferenceCaller1 = BindFirstOpaque<Function2<const Environment &, FirstArgument, void, func>>;
 
 /// \brief Forms a Callback from a non-const Environment pointer and a free function which operates on a non-const Environment pointer.
-template<typename Environment, void( *func ) (Environment*)>
-class PointerCaller : public BindFirstOpaque< Function1<Environment*, void, func> >
-{
-public:
-	PointerCaller( Environment* environment ) : BindFirstOpaque< Function1<Environment*, void, func> >( environment ){
-	}
-};
+template<class Environment, void(*func)(Environment *)>
+using PointerCaller = BindFirstOpaque<Function1<Environment *, void, func>>;
 
 /// \brief Forms a Callback from a const Environment pointer and a free function which operates on a const Environment pointer.
-template<typename Environment, void( *func ) (const Environment*)>
-class ConstPointerCaller : public BindFirstOpaque< Function1<const Environment*, void, func> >
-{
-public:
-	ConstPointerCaller( const Environment* environment ) : BindFirstOpaque< Function1<const Environment*, void, func> >( environment ){
-	}
-};
+template<class Environment, void(*func)(const Environment *)>
+using ConstPointerCaller = BindFirstOpaque<Function1<const Environment *, void, func>>;
 
 /// \brief Forms a Callback from a non-const Environment pointer and a free function which operates on a non-const Environment pointer and one other argument.
-template<typename Environment, typename FirstArgument, void( *func ) ( Environment*, FirstArgument )>
-class PointerCaller1 : public BindFirstOpaque1< Function2<Environment*, FirstArgument, void, func> >
-{
-public:
-	PointerCaller1( Environment* environment ) : BindFirstOpaque1< Function2<Environment*, FirstArgument, void, func> >( environment ){
-	}
-};
+template<class Environment, class FirstArgument, void(*func)(Environment *, FirstArgument)>
+using PointerCaller1 = BindFirstOpaque<Function2<Environment *, FirstArgument, void, func>>;
 
 /// \brief Forms a Callback from a const Environment pointer and a free function which operates on a const Environment pointer and one other argument.
-template<typename Environment, typename FirstArgument, void( *func ) ( const Environment*, FirstArgument )>
-class ConstPointerCaller1 : public BindFirstOpaque1< Function2<const Environment*, FirstArgument, void, func> >
-{
-public:
-	ConstPointerCaller1( const Environment* environment ) : BindFirstOpaque1< Function2<const Environment*, FirstArgument, void, func> >( environment ){
-	}
-};
+template<class Environment, class FirstArgument, void(*func)(const Environment *, FirstArgument)>
+using ConstPointerCaller1 = BindFirstOpaque<Function2<const Environment *, FirstArgument, void, func>>;
 
 /// \brief Forms a Callback from a free function which takes no arguments.
-template<void( *func ) ( )>
-class FreeCaller : public BindFirstOpaque< Caller0To1< Function0<void, func> > >
+template<void(*func)()>
+class FreeCaller : public BindFirstOpaque<Caller0To1<Function0<void, func>>>
 {
 public:
-	FreeCaller() : BindFirstOpaque< Caller0To1< Function0<void, func> > >( 0 ){
+	FreeCaller() : BindFirstOpaque<Caller0To1<Function0<void, func>>>( 0 ){
 	}
 };
 
 /// \brief Forms a Callback from a free function which takes a single argument.
-template<typename FirstArgument, void( *func ) (FirstArgument)>
-class FreeCaller1 : public BindFirstOpaque1< Caller1To2< Function1<FirstArgument, void, func> > >
+template<class FirstArgument, void(*func)(FirstArgument)>
+class FreeCaller1 : public BindFirstOpaque<Caller1To2<Function1<FirstArgument, void, func>>>
 {
 public:
-	FreeCaller1() : BindFirstOpaque1< Caller1To2< Function1<FirstArgument, void, func> > >( 0 ){
+	FreeCaller1() : BindFirstOpaque<Caller1To2<Function1<FirstArgument, void, func>>>( 0 ){
 	}
 };
 
@@ -636,19 +426,19 @@ inline Callback makeCallback( const Functor& functor ){
 
 /// \brief  Constructs a Callback1 from a non-const \p functor with one argument.
 ///
-/// \param Functor Must define \c first_argument_type and \c operator()(first_argument_type).
+/// \param Functor Must define \c operator()(argument) and its signature as \c func.
 template<typename Functor>
-inline Callback1<typename Functor::first_argument_type> makeCallback1( Functor& functor ){
-	typedef typename Functor::first_argument_type FirstArgument;
+inline Callback1<get_argument<Functor, 0>> makeCallback1( Functor& functor ){
+	typedef get_argument<Functor, 0> FirstArgument;
 	return Callback1<FirstArgument>( MemberCaller1<Functor, FirstArgument, &Functor::operator()>( functor ) );
 }
 
 /// \brief  Constructs a Callback1 from a const \p functor with one argument.
 ///
-/// \param Functor Must define \c first_argument_type and const \c operator()(first_argument_type).
+/// \param Functor Must define const \c operator()(argument) and its signature as \c func.
 template<typename Functor>
-inline Callback1<typename Functor::first_argument_type> makeCallback1( const Functor& functor ){
-	typedef typename Functor::first_argument_type FirstArgument;
+inline Callback1<get_argument<Functor, 0>> makeCallback1( const Functor& functor ){
+	typedef get_argument<Functor, 0> FirstArgument;
 	return Callback1<FirstArgument>( ConstMemberCaller1<Functor, FirstArgument, &Functor::operator()>( functor ) );
 }
 
diff --git a/libs/generic/functional.h b/libs/generic/functional.h
index 735b54f5..5168f11d 100644
--- a/libs/generic/functional.h
+++ b/libs/generic/functional.h
@@ -1,315 +1,225 @@
 
 #pragma once
 
-template<typename Object, typename R, R( Object::*member ) ( )>
-class Member
+#include <tuple>
+
+namespace detail {
+	template<class F>
+	struct Fn;
+
+	template<class R, class... Ts>
+	struct Fn<R(Ts...)>
+	{
+		using result_type = R;
+
+		template<int N>
+		using get = typename std::tuple_element<N, std::tuple<Ts...>>::type;
+	};
+}
+
+template<class Caller>
+using get_result_type = typename detail::Fn<typename Caller::func>::result_type;
+
+template<class Caller, int N>
+using get_argument = typename detail::Fn<typename Caller::func>::template get<N>;
+
+template<class Object, class F>
+class MemberN;
+
+template<class Object, class R, class... Ts>
+class MemberN<Object, R(Ts...)>
 {
 public:
-	typedef Object& first_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object ){
-		return ( object.*member )();
+	template<R(Object::*f)(Ts...)>
+	class instance
+	{
+	public:
+		using func = R(Object &, Ts...);
+
+		static R call( Object& object, Ts... args ){
+			return ( object.*f )( args... );
+		}
+	};
+};
+
+template<class Object, class F>
+class ConstMemberN;
+
+template<class Object, class R, class... Ts>
+class ConstMemberN<Object, R(Ts...)>
+{
+public:
+	template<R(Object::*f)(Ts...) const>
+	class instance
+	{
+	public:
+		using func = R(const Object &, Ts...);
+
+		static R call( const Object& object, Ts... args ){
+			return ( object.*f )( args... );
+		}
+	};
+};
+
+template<class F>
+class FunctionN;
+
+template<class R, class... Ts>
+class FunctionN<R(Ts...)>
+{
+public:
+	template<R(*f)(Ts...)>
+	class instance
+	{
+	public:
+		using func = R(Ts...);
+
+		static R call( Ts... args ){
+			return ( f )( args... );
+		}
+	};
+};
+
+template<class Caller, class F>
+class CallerShiftFirst;
+
+template<class Caller, class R, class FirstArgument, class... Ts>
+class CallerShiftFirst<Caller, R(FirstArgument, Ts...)>
+{
+public:
+	using func = R(FirstArgument, Ts...);
+
+	static R call( FirstArgument, Ts... args ){
+		return Caller::call( args... );
 	}
 };
 
-template<typename Object, typename R, R( Object::*member ) ( ) const>
-class ConstMember
+template<class Functor, class F>
+class FunctorNInvoke;
+
+namespace detail {
+	template<int ...>
+	struct seq
+	{
+	};
+
+	template<int N, int... S>
+	struct gens : gens<N - 1, N - 1, S...>
+	{
+	};
+
+	template<int... S>
+	struct gens<0, S...>
+	{
+		using type = seq<S...>;
+	};
+
+	template<int N>
+	using seq_new = typename gens<N>::type;
+}
+
+template<class Functor, class R, class... Ts>
+class FunctorNInvoke<Functor, R(Ts...)>
 {
+	std::tuple<Ts...> args;
+
+	template<class T>
+	struct caller;
+
+	template<int ...I>
+	struct caller<detail::seq<I...>>
+	{
+		static inline R call( FunctorNInvoke<Functor, R(Ts...)> *self, Functor functor ){
+			(void) self;
+			return functor( std::get<I>( self->args )... );
+		}
+	};
+
 public:
-	typedef const Object& first_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object ){
-		return ( object.*member )();
+	FunctorNInvoke( Ts... args ) : args( args... ){
+	}
+
+	inline R operator()( Functor functor ) {
+		return caller<detail::seq_new<sizeof...(Ts)>>::call( this, functor );
 	}
 };
 
-template<typename Object, typename A1, typename R, R( Object::*member ) (A1)>
-class Member1
-{
-public:
-	typedef Object& first_argument_type;
-	typedef A1 second_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object, second_argument_type a1 ){
-		return ( object.*member )( a1 );
-	}
-};
+template<class Functor>
+using FunctorInvoke = FunctorNInvoke<Functor, typename Functor::func>;
 
-template<typename Object, typename A1, typename R, R( Object::*member ) (A1) const>
-class ConstMember1
-{
-public:
-	typedef const Object& first_argument_type;
-	typedef A1 second_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object, second_argument_type a1 ){
-		return ( object.*member )( a1 );
-	}
-};
+template<class Object, class R, R(Object::*member)()>
+using Member = typename MemberN<Object, R()>::template instance<member>;
 
-template<typename Object, typename A2, typename A3, typename R, R( Object::*member ) ( A2, A3 )>
-class Member2
-{
-public:
-	typedef Object& first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object, second_argument_type a2, third_argument_type a3 ){
-		return ( object.*member )( a2, a3 );
-	}
-};
+template<class Object, class R, R(Object::*member)() const>
+using ConstMember = typename ConstMemberN<Object, R()>::template instance<member>;
 
-template<typename Object, typename A2, typename A3, typename R, R( Object::*member ) ( A2, A3 ) const>
-class ConstMember2
-{
-public:
-	typedef const Object& first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object, second_argument_type a2, third_argument_type a3 ){
-		return ( object.*member )( a2, a3 );
-	}
-};
+template<class Object, class A1, class R, R(Object::*member)(A1)>
+using Member1 = typename MemberN<Object, R(A1)>::template instance<member>;
 
-template<typename Object, typename A2, typename A3, typename A4, typename R, R( Object::*member ) ( A2, A3, A4 )>
-class Member3
-{
-public:
-	typedef Object& first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef A4 fourth_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ){
-		return ( object.*member )( a2, a3, a4 );
-	}
-};
+template<class Object, class A1, class R, R(Object::*member)(A1) const>
+using ConstMember1 = typename ConstMemberN<Object, R(A1)>::template instance<member>;
 
-template<typename Object, typename A2, typename A3, typename A4, typename R, R( Object::*member ) ( A2, A3, A4 ) const>
-class ConstMember3
-{
-public:
-	typedef const Object& first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef A4 fourth_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type object, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ){
-		return ( object.*member )( a2, a3, a4 );
-	}
-};
+template<class Object, class A1, class A2, class R, R(Object::*member)(A1, A2)>
+using Member2 = typename MemberN<Object, R(A1, A2)>::template instance<member>;
 
-template<typename R, R( *func ) ( )>
-class Function0
-{
-public:
-	typedef R result_type;
-	static result_type call(){
-		return (func)( );
-	}
-};
+template<class Object, class A1, class A2, class R, R(Object::*member)(A1, A2) const>
+using ConstMember2 = typename ConstMemberN<Object, R(A1, A2)>::template instance<member>;
 
-template<typename A1, typename R, R( *func ) (A1)>
-class Function1
-{
-public:
-	typedef A1 first_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type a1 ){
-		return (func)( a1 );
-	}
-};
+template<class Object, class A1, class A2, class A3, class R, R(Object::*member)(A1, A2, A3)>
+using Member3 = typename MemberN<Object, R(A1, A2, A3)>::template instance<member>;
 
-template<typename A1, typename A2, typename R, R( *func ) ( A1, A2 )>
-class Function2
-{
-public:
-	typedef A1 first_argument_type;
-	typedef A2 second_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2 ){
-		return (func)( a1, a2 );
-	}
-};
+template<class Object, class A1, class A2, class A3, class R, R(Object::*member)(A1, A2, A3) const>
+using ConstMember3 = typename ConstMemberN<Object, R(A1, A2, A3)>::template instance<member>;
 
-template<typename A1, typename A2, typename A3, typename R, R( *func ) ( A1, A2, A3 )>
-class Function3
-{
-public:
-	typedef A1 first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2, third_argument_type a3 ){
-		return (func)( a1, a2, a3 );
-	}
-};
+template<class R, R(*func)()>
+using Function0 = typename FunctionN<R()>::template instance<func>;
 
-template<typename A1, typename A2, typename A3, typename A4, typename R, R( *func ) ( A1, A2, A3, A4 )>
-class Function4
-{
-public:
-	typedef A1 first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef A4 fourth_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ){
-		return (func)( a1, a2, a3, a4 );
-	}
-};
+template<class A1, class R, R(*func)(A1)>
+using Function1 = typename FunctionN<R(A1)>::template instance<func>;
 
-template<typename A1, typename A2, typename A3, typename A4, typename A5, typename R, R( *func ) ( A1, A2, A3, A4, A5 )>
-class Function5
-{
-public:
-	typedef A1 first_argument_type;
-	typedef A2 second_argument_type;
-	typedef A3 third_argument_type;
-	typedef A4 fourth_argument_type;
-	typedef A5 fifth_argument_type;
-	typedef R result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2, third_argument_type a3, fourth_argument_type a4, fifth_argument_type a5 ){
-		return (func)( a1, a2, a3, a4, a5 );
-	}
-};
+template<class A1, class A2, class R, R(*func)(A1, A2)>
+using Function2 = typename FunctionN<R(A1, A2)>::template instance<func>;
 
-template<typename Caller, typename FirstArgument = void*>
-class Caller0To1
-{
-public:
-	typedef FirstArgument first_argument_type;
-	typedef typename Caller::result_type result_type;
-	static result_type call( first_argument_type ){
-		return Caller::call();
-	}
-};
+template<class A1, class A2, class A3, class R, R(*func)(A1, A2, A3)>
+using Function3 = typename FunctionN<R(A1, A2, A3)>::template instance<func>;
 
-template<typename Caller, typename FirstArgument = void*>
-class Caller1To2
-{
-public:
-	typedef FirstArgument first_argument_type;
-	typedef typename Caller::first_argument_type second_argument_type;
-	typedef typename Caller::result_type result_type;
-	static result_type call( first_argument_type, second_argument_type a2 ){
-		return Caller::call( a2 );
-	}
-};
+template<class A1, class A2, class A3, class A4, class R, R(*func)(A1, A2, A3, A4)>
+using Function4 = typename FunctionN<R(A1, A2, A3, A4)>::template instance<func>;
 
-template<typename Caller, typename FirstArgument = void*>
-class Caller2To3
-{
-public:
-	typedef FirstArgument first_argument_type;
-	typedef typename Caller::first_argument_type second_argument_type;
-	typedef typename Caller::second_argument_type third_argument_type;
-	typedef typename Caller::result_type result_type;
-	static result_type call( first_argument_type, second_argument_type a2, third_argument_type a3 ){
-		return Caller::call( a2, a3 );
-	}
-};
+template<class A1, class A2, class A3, class A4, class A5, class R, R(*func)(A1, A2, A3, A4, A5)>
+using Function5 = typename FunctionN<R(A1, A2, A3, A4, A5)>::template instance<func>;
 
-template<typename Caller, typename FirstArgument = void*>
-class Caller3To4
-{
-public:
-	typedef FirstArgument first_argument_type;
-	typedef typename Caller::first_argument_type second_argument_type;
-	typedef typename Caller::second_argument_type third_argument_type;
-	typedef typename Caller::third_argument_type fourth_argument_type;
-	typedef typename Caller::result_type result_type;
-	static result_type call( first_argument_type, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ){
-		return Caller::call( a2, a3, a4 );
-	}
-};
+template<class Caller, class FirstArgument = void *>
+using Caller0To1 = CallerShiftFirst<Caller, get_result_type<Caller>(
+        FirstArgument
+)>;
 
-template<typename Caller, typename FirstArgument = void*>
-class Caller4To5
-{
-public:
-	typedef FirstArgument first_argument_type;
-	typedef typename Caller::first_argument_type second_argument_type;
-	typedef typename Caller::second_argument_type third_argument_type;
-	typedef typename Caller::third_argument_type fourth_argument_type;
-	typedef typename Caller::fourth_argument_type fifth_argument_type;
-	typedef typename Caller::result_type result_type;
-	static result_type call( first_argument_type, second_argument_type a2, third_argument_type a3, fourth_argument_type a4, fifth_argument_type a5 ){
-		return Caller::call( a2, a3, a4, a5 );
-	}
-};
+template<class Caller, class FirstArgument = void *>
+using Caller1To2 = CallerShiftFirst<Caller, get_result_type<Caller>(
+        FirstArgument,
+        get_argument<Caller, 0>
+)>;
 
-template<typename Functor>
-class FunctorInvoke
-{
-public:
-	typedef typename Functor::result_type result_type;
-	inline result_type operator()( Functor functor ){
-		return functor();
-	}
-};
+template<class Caller, class FirstArgument = void *>
+using Caller2To3 = CallerShiftFirst<Caller, get_result_type<Caller>(
+        FirstArgument,
+        get_argument<Caller, 0>,
+        get_argument<Caller, 1>
+)>;
 
-template<typename Functor>
-class Functor1Invoke
-{
-	typename Functor::first_argument_type a1;
-public:
-	typedef typename Functor::first_argument_type first_argument_type;
-	typedef typename Functor::result_type result_type;
-	Functor1Invoke( first_argument_type a1 ) : a1( a1 ){
-	}
-	inline result_type operator()( Functor functor ){
-		return functor( a1 );
-	}
-};
+template<class Caller, class FirstArgument = void *>
+using Caller3To4 = CallerShiftFirst<Caller, get_result_type<Caller>(
+        FirstArgument,
+        get_argument<Caller, 0>,
+        get_argument<Caller, 1>,
+        get_argument<Caller, 2>
+)>;
 
-template<typename Functor>
-class Functor2Invoke
-{
-	typename Functor::first_argument_type a1;
-	typename Functor::second_argument_type a2;
-public:
-	typedef typename Functor::first_argument_type first_argument_type;
-	typedef typename Functor::second_argument_type second_argument_type;
-	typedef typename Functor::result_type result_type;
-	Functor2Invoke( first_argument_type a1, second_argument_type a2 )
-		: a1( a1 ), a2( a2 ){
-	}
-	inline result_type operator()( Functor functor ){
-		return functor( a1, a2 );
-	}
-};
-
-template<typename Functor>
-class Functor3Invoke
-{
-	typename Functor::first_argument_type a1;
-	typename Functor::second_argument_type a2;
-	typename Functor::third_argument_type a3;
-public:
-	typedef typename Functor::first_argument_type first_argument_type;
-	typedef typename Functor::second_argument_type second_argument_type;
-	typedef typename Functor::third_argument_type third_argument_type;
-	typedef typename Functor::result_type result_type;
-	Functor3Invoke( first_argument_type a1, second_argument_type a2, third_argument_type a3 )
-		: a1( a1 ), a2( a2 ), a3( a3 ){
-	}
-	inline result_type operator()( Functor functor ){
-		return functor( a1, a2, a3 );
-	}
-};
-
-template<typename Other, typename True, typename False, typename Type>
-class TypeEqual
-{
-public:
-	typedef False type;
-};
-template<typename Other, typename True, typename False>
-class TypeEqual<Other, True, False, Other>
-{
-public:
-	typedef True type;
-};
+template<class Caller, class FirstArgument = void *>
+using Caller4To5 = CallerShiftFirst<Caller, get_result_type<Caller>(
+        FirstArgument,
+        get_argument<Caller, 0>,
+        get_argument<Caller, 1>,
+        get_argument<Caller, 2>,
+        get_argument<Caller, 3>
+)>;
diff --git a/libs/signal/isignal.h b/libs/signal/isignal.h
index 7c274399..05e5f2c1 100644
--- a/libs/signal/isignal.h
+++ b/libs/signal/isignal.h
@@ -21,182 +21,149 @@ public:
 const SignalHandlerResult SIGNAL_CONTINUE_EMISSION = SignalHandlerResult( false );
 const SignalHandlerResult SIGNAL_STOP_EMISSION = SignalHandlerResult( true );
 
-template<typename Caller>
-class SignalHandlerCaller1
+template<class Caller, class F>
+class SignalHandlerCallerN;
+
+template<class Caller, class R, class... Ts>
+class SignalHandlerCallerN<Caller, R(Ts...)>
 {
 public:
-	typedef typename Caller::first_argument_type first_argument_type;
-	typedef SignalHandlerResult result_type;
-	static result_type call( first_argument_type a1 ){
-		Caller::call( a1 );
+	using func = SignalHandlerResult(Ts...);
+
+	static SignalHandlerResult call( Ts... args ) {
+		Caller::call( args... );
 		return SIGNAL_CONTINUE_EMISSION;
 	}
 };
 
-template<typename Caller>
-class SignalHandlerCaller2
-{
-public:
-	typedef typename Caller::first_argument_type first_argument_type;
-	typedef typename Caller::second_argument_type second_argument_type;
-	typedef SignalHandlerResult result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2 ){
-		Caller::call( a1, a2 );
-		return SIGNAL_CONTINUE_EMISSION;
-	}
-};
+template<class Caller>
+using SignalHandlerCaller = SignalHandlerCallerN<Caller, typename Caller::func>;
+
+template<class Caller>
+using SignalHandlerCaller1 = SignalHandlerCaller<Caller>;
+
+template<class Caller>
+using SignalHandlerCaller2 = SignalHandlerCaller<Caller>;
 
 template<typename Caller>
-class SignalHandlerCaller3
-{
-public:
-	typedef typename Caller::first_argument_type first_argument_type;
-	typedef typename Caller::second_argument_type second_argument_type;
-	typedef typename Caller::third_argument_type third_argument_type;
-	typedef SignalHandlerResult result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2, third_argument_type a3 ){
-		Caller::call( a1, a2, a3 );
-		return SIGNAL_CONTINUE_EMISSION;
-	}
-};
+using SignalHandlerCaller3 = SignalHandlerCaller<Caller>;
 
 template<typename Caller>
-class SignalHandlerCaller4
+using SignalHandlerCaller4 = SignalHandlerCaller<Caller>;
+
+template<typename Other, typename True, typename False, typename Type>
+class TypeEqual
 {
 public:
-	typedef typename Caller::first_argument_type first_argument_type;
-	typedef typename Caller::second_argument_type second_argument_type;
-	typedef typename Caller::third_argument_type third_argument_type;
-	typedef typename Caller::fourth_argument_type fourth_argument_type;
-	typedef SignalHandlerResult result_type;
-	static result_type call( first_argument_type a1, second_argument_type a2, third_argument_type a3, fourth_argument_type a4 ){
-		Caller::call( a1, a2, a3, a4 );
-		return SIGNAL_CONTINUE_EMISSION;
-	}
+	using type = False;
 };
 
-class SignalHandler : public Callback0<SignalHandlerResult>
+template<typename Other, typename True, typename False>
+class TypeEqual<Other, True, False, Other>
+{
+public:
+	using type = True;
+};
+
+template<class CB, template<class T> class Wrapper>
+class SignalHandlerN : public CB
 {
 public:
 	template<typename Caller>
-	SignalHandler( const BindFirstOpaque<Caller>& caller )
-		: Callback0<SignalHandlerResult>( BindFirstOpaque<typename TypeEqual<
-		                                                      SignalHandlerResult,
-		                                                      Caller,
-		                                                      SignalHandlerCaller1<Caller>,
-		                                                      typename Caller::result_type
-		                                                      >::type>( caller.getBound() ) ){
+	SignalHandlerN( const BindFirstOpaque<Caller>& caller )
+		: CB( BindFirstOpaque<typename TypeEqual<
+			SignalHandlerResult,
+			Caller,
+			Wrapper<Caller>,
+			get_result_type<Caller>
+			>::type>( caller.getBound() ) ){
 	}
 };
 
+class SignalHandler : public SignalHandlerN<Callback0<SignalHandlerResult>, SignalHandlerCaller1>
+{
+	using SignalHandlerN<Callback0<SignalHandlerResult>, SignalHandlerCaller1>::SignalHandlerN;
+};
+
 template<typename Caller>
 inline SignalHandler makeSignalHandler( const BindFirstOpaque<Caller>& caller ){
 	return SignalHandler( caller );
 }
 template<typename Caller>
-inline SignalHandler makeSignalHandler( const Caller& caller, typename Caller::first_argument_type callee ){
+inline SignalHandler makeSignalHandler( const Caller& caller, get_argument<Caller, 0> callee ){
 	return SignalHandler( BindFirstOpaque<Caller>( callee ) );
 }
 
-
 template<typename FirstArgument>
-class SignalHandler1 : public Callback1<FirstArgument, SignalHandlerResult>
+class SignalHandler1 : public SignalHandlerN<Callback1<FirstArgument, SignalHandlerResult>, SignalHandlerCaller2>
 {
-public:
-	template<typename Caller>
-	SignalHandler1( const BindFirstOpaque1<Caller>& caller )
-		: Callback1<FirstArgument, SignalHandlerResult>( BindFirstOpaque1<typename TypeEqual<
-		                                                                      SignalHandlerResult,
-		                                                                      Caller,
-		                                                                      SignalHandlerCaller2<Caller>,
-		                                                                      typename Caller::result_type
-		                                                                      >::type>( caller.getBound() ) ){
-	}
+    using SignalHandlerN<Callback1<FirstArgument, SignalHandlerResult>, SignalHandlerCaller2>::SignalHandlerN;
 };
 
 template<typename Caller>
-inline SignalHandler1<typename Caller::second_argument_type> makeSignalHandler1( const BindFirstOpaque1<Caller>& caller ){
-	return SignalHandler1<typename Caller::second_argument_type>( caller );
+inline SignalHandler1<get_argument<Caller, 1>> makeSignalHandler1(const BindFirstOpaque<Caller>& caller){
+	return SignalHandler1<get_argument<Caller, 1>>( caller );
 }
 template<typename Caller>
-inline SignalHandler1<typename Caller::second_argument_type> makeSignalHandler1( const Caller& caller, typename Caller::first_argument_type callee ){
-	return SignalHandler1<typename Caller::second_argument_type>( BindFirstOpaque1<Caller>( callee ) );
+inline SignalHandler1<get_argument<Caller, 1>>
+makeSignalHandler1(const Caller &caller, get_argument<Caller, 0> callee) {
+    return SignalHandler1<get_argument<Caller, 1>>(BindFirstOpaque<Caller>(callee));
 }
 
-
 template<typename FirstArgument, typename SecondArgument>
-class SignalHandler2 : public Callback2<FirstArgument, SecondArgument, SignalHandlerResult>
+class SignalHandler2 : public SignalHandlerN<Callback2<FirstArgument, SecondArgument, SignalHandlerResult>, SignalHandlerCaller3>
 {
-public:
-	template<typename Caller>
-	SignalHandler2( const BindFirstOpaque2<Caller>& caller )
-		: Callback2<FirstArgument, SecondArgument, SignalHandlerResult>( BindFirstOpaque2<typename TypeEqual<
-		                                                                                      SignalHandlerResult,
-		                                                                                      Caller,
-		                                                                                      SignalHandlerCaller3<Caller>,
-		                                                                                      typename Caller::result_type
-		                                                                                      >::type>( caller.getBound() ) ){
-	}
+	using SignalHandlerN<Callback2<FirstArgument, SecondArgument, SignalHandlerResult>, SignalHandlerCaller3>::SignalHandlerN;
 };
 
 template<typename Caller>
 inline SignalHandler2<
-        typename Caller::second_argument_type,
-        typename Caller::third_argument_type
-> makeSignalHandler2( const BindFirstOpaque2<Caller>& caller ){
+            get_argument<Caller, 1>,
+            get_argument<Caller, 2>
+> makeSignalHandler2( const BindFirstOpaque<Caller>& caller ){
 	return SignalHandler2<
-	            typename Caller::second_argument_type,
-	            typename Caller::third_argument_type
+	            get_argument<Caller, 1>,
+	            get_argument<Caller, 2>
 	       >( caller );
 }
 template<typename Caller>
 inline SignalHandler2<
-            typename Caller::second_argument_type,
-            typename Caller::third_argument_type
-> makeSignalHandler2( const Caller& caller, typename Caller::first_argument_type callee ){
+            get_argument<Caller, 1>,
+            get_argument<Caller, 2>
+> makeSignalHandler2( const Caller& caller, get_argument<Caller, 0> callee ){
 	return SignalHandler2<
-	            typename Caller::second_argument_type,
-	            typename Caller::third_argument_type
-	       >( BindFirstOpaque2<Caller>( callee ) );
+	            get_argument<Caller, 1>,
+	            get_argument<Caller, 2>
+	       >( BindFirstOpaque<Caller>( callee ) );
 }
 
-
 template<typename FirstArgument, typename SecondArgument, typename ThirdArgument>
-class SignalHandler3 : public Callback3<FirstArgument, SecondArgument, ThirdArgument, SignalHandlerResult>
+class SignalHandler3 : public SignalHandlerN<Callback3<FirstArgument, SecondArgument, ThirdArgument, SignalHandlerResult>, SignalHandlerCaller4>
 {
-public:
-	template<typename Caller>
-	SignalHandler3( const BindFirstOpaque3<Caller>& caller )
-		: Callback3<FirstArgument, SecondArgument, ThirdArgument, SignalHandlerResult>( BindFirstOpaque3<typename TypeEqual<
-		                                                                                                     SignalHandlerResult,
-		                                                                                                     Caller,
-		                                                                                                     SignalHandlerCaller4<Caller>,
-		                                                                                                     typename Caller::result_type
-		                                                                                                     >::type>( caller.getBound() ) ){
-	}
+	using SignalHandlerN<Callback3<FirstArgument, SecondArgument, ThirdArgument, SignalHandlerResult>, SignalHandlerCaller4>::SignalHandlerN;
 };
 
 template<typename Caller>
 inline SignalHandler3<
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::fourth_argument_type
-> makeSignalHandler3( const BindFirstOpaque3<Caller>& caller ){
+         get_argument<Caller, 1>,
+         get_argument<Caller, 2>,
+         get_argument<Caller, 3>
+> makeSignalHandler3( const BindFirstOpaque<Caller>& caller ){
 	return SignalHandler3<
-	            typename Caller::second_argument_type,
-	            typename Caller::third_argument_type,
-	            typename Caller::fourth_argument_type
+	            get_argument<Caller, 1>,
+	            get_argument<Caller, 2>,
+	            get_argument<Caller, 3>
 	       >( caller );
 }
 template<typename Caller>
 inline SignalHandler3<
-         typename Caller::second_argument_type,
-         typename Caller::third_argument_type,
-         typename Caller::fourth_argument_type
-> makeSignalHandler3( const Caller& caller, typename Caller::first_argument_type callee ){
+        get_argument<Caller, 1>,
+        get_argument<Caller, 2>,
+        get_argument<Caller, 3>
+> makeSignalHandler3( const Caller& caller, get_argument<Caller, 0> callee ){
 	return SignalHandler3<
-	            typename Caller::second_argument_type,
-	            typename Caller::third_argument_type,
-	            typename Caller::fourth_argument_type
-	       >( BindFirstOpaque3<Caller>( callee ) );
+	            get_argument<Caller, 1>,
+	            get_argument<Caller, 2>,
+	            get_argument<Caller, 3>
+	       >( BindFirstOpaque<Caller>( callee ) );
 }
diff --git a/libs/signal/signal.h b/libs/signal/signal.h
index e1e1333b..f22ec29d 100644
--- a/libs/signal/signal.h
+++ b/libs/signal/signal.h
@@ -314,7 +314,7 @@ class Signal1 : public SignalBase< SignalHandler1<FirstArgument> >
 	typedef SignalBase< SignalHandler1<FirstArgument> > Base;
 public:
 	void operator()( FirstArgument a1 ) const {
-		invokeSignalHandlers( Base::begin(), Base::end(), Functor1Invoke<typename Base::handler_type>( a1 ) );
+		invokeSignalHandlers( Base::begin(), Base::end(), FunctorInvoke<typename Base::handler_type>( a1 ) );
 	}
 };
 
@@ -324,7 +324,7 @@ class Signal2 : public SignalBase< SignalHandler2<FirstArgument, SecondArgument>
 	typedef SignalBase< SignalHandler2<FirstArgument, SecondArgument> > Base;
 public:
 	void operator()( FirstArgument a1, SecondArgument a2 ) const {
-		invokeSignalHandlers( Base::begin(), Base::end(), Functor2Invoke<typename Base::handler_type>( a1, a2 ) );
+		invokeSignalHandlers( Base::begin(), Base::end(), FunctorInvoke<typename Base::handler_type>( a1, a2 ) );
 	}
 };
 
@@ -334,6 +334,6 @@ class Signal3 : public SignalBase< SignalHandler3<FirstArgument, SecondArgument,
 	typedef SignalBase< SignalHandler3<FirstArgument, SecondArgument, ThirdArgument> > Base;
 public:
 	void operator()( FirstArgument a1, SecondArgument a2, ThirdArgument a3 ) const {
-		invokeSignalHandlers( Base::begin(), Base::end(), Functor3Invoke<typename Base::handler_type>( a1, a2, a3 ) );
+		invokeSignalHandlers( Base::begin(), Base::end(), FunctorInvoke<typename Base::handler_type>( a1, a2, a3 ) );
 	}
 };
diff --git a/libs/stringio.h b/libs/stringio.h
index b296f9b6..320114f8 100644
--- a/libs/stringio.h
+++ b/libs/stringio.h
@@ -398,12 +398,12 @@ typedef ConstReferenceCaller1<StringImportCallback, CopiedString, CopiedString_t
 
 template<typename Caller>
 inline StringImportCallback makeCopiedStringStringImportCallback( const Caller& caller ){
-	return StringImportCallback( caller.getEnvironment(), ImportConvert1<StringImportCallback::first_argument_type, Caller, CopiedStringFromString>::thunk );
+	return StringImportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringImportCallback, 0>, Caller, CopiedStringFromString>::thunk );
 }
 
 template<typename Caller>
 inline StringExportCallback makeCopiedStringStringExportCallback( const Caller& caller ){
-	return StringExportCallback( caller.getEnvironment(), ImportConvert1<StringExportCallback::first_argument_type, Caller, CopiedStringToString>::thunk );
+	return StringExportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringExportCallback, 0>, Caller, CopiedStringToString>::thunk );
 }
 
 
@@ -428,12 +428,12 @@ typedef ConstReferenceCaller1<StringImportCallback, bool, Bool_toString> BoolToS
 
 template<typename Caller>
 inline StringImportCallback makeBoolStringImportCallback( const Caller& caller ){
-	return StringImportCallback( caller.getEnvironment(), ImportConvert1<StringImportCallback::first_argument_type, Caller, BoolFromString>::thunk );
+	return StringImportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringImportCallback, 0>, Caller, BoolFromString>::thunk );
 }
 
 template<typename Caller>
 inline StringExportCallback makeBoolStringExportCallback( const Caller& caller ){
-	return StringExportCallback( caller.getEnvironment(), ImportConvert1<StringExportCallback::first_argument_type, Caller, BoolToString>::thunk );
+	return StringExportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringExportCallback, 0>, Caller, BoolToString>::thunk );
 }
 
 
@@ -458,12 +458,12 @@ typedef ConstReferenceCaller1<StringImportCallback, int, Int_toString> IntToStri
 
 template<typename Caller>
 inline StringImportCallback makeIntStringImportCallback( const Caller& caller ){
-	return StringImportCallback( caller.getEnvironment(), ImportConvert1<StringImportCallback::first_argument_type, Caller, IntFromString>::thunk );
+	return StringImportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringImportCallback, 0>, Caller, IntFromString>::thunk );
 }
 
 template<typename Caller>
 inline StringExportCallback makeIntStringExportCallback( const Caller& caller ){
-	return StringExportCallback( caller.getEnvironment(), ImportConvert1<StringExportCallback::first_argument_type, Caller, IntToString>::thunk );
+	return StringExportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringExportCallback, 0>, Caller, IntToString>::thunk );
 }
 
 
@@ -489,10 +489,10 @@ typedef ConstReferenceCaller1<StringImportCallback, std::size_t, Size_toString>
 
 template<typename Caller>
 inline StringImportCallback makeSizeStringImportCallback( const Caller& caller ){
-	return StringImportCallback( caller.getEnvironment(), ImportConvert1<StringImportCallback::first_argument_type, Caller, SizeFromString>::thunk );
+	return StringImportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringImportCallback, 0>, Caller, SizeFromString>::thunk );
 }
 
 template<typename Caller>
 inline StringExportCallback makeSizeStringExportCallback( const Caller& caller ){
-	return StringExportCallback( caller.getEnvironment(), ImportConvert1<StringExportCallback::first_argument_type, Caller, SizeToString>::thunk );
+	return StringExportCallback( caller.getEnvironment(), ImportConvert1<get_argument<StringExportCallback, 0>, Caller, SizeToString>::thunk );
 }
diff --git a/radiant/csg.cpp b/radiant/csg.cpp
index f68b5579..e4c57f5d 100644
--- a/radiant/csg.cpp
+++ b/radiant/csg.cpp
@@ -473,11 +473,9 @@ class Dereference
 {
 	const Functor& functor;
 public:
-	typedef typename RemoveReference<typename Functor::first_argument_type>::type* first_argument_type;
-	typedef typename Functor::result_type result_type;
 	Dereference( const Functor& functor ) : functor( functor ){
 	}
-	result_type operator()( first_argument_type firstArgument ) const {
+	get_result_type<Functor> operator()( typename RemoveReference<get_argument<Functor, 0>>::type *firstArgument ) const {
 		return functor( *firstArgument );
 	}
 };
@@ -499,15 +497,13 @@ Face* Brush_findIf( const Brush& brush, const Predicate& predicate ){
 template<typename Caller>
 class BindArguments1
 {
-	typedef typename Caller::second_argument_type FirstBound;
+	typedef get_argument<Caller, 1> FirstBound;
 	FirstBound firstBound;
 public:
-	typedef typename Caller::result_type result_type;
-	typedef typename Caller::first_argument_type first_argument_type;
 	BindArguments1( FirstBound firstBound )
 		: firstBound( firstBound ){
 	}
-	result_type operator()( first_argument_type firstArgument ) const {
+	get_result_type<Caller> operator()( get_argument<Caller, 0> firstArgument ) const {
 		return Caller::call( firstArgument, firstBound );
 	}
 };
@@ -515,17 +511,15 @@ public:
 template<typename Caller>
 class BindArguments2
 {
-	typedef typename Caller::second_argument_type FirstBound;
-	typedef typename Caller::third_argument_type SecondBound;
+	typedef get_argument<Caller, 1> FirstBound;
+	typedef get_argument<Caller, 2> SecondBound;
 	FirstBound firstBound;
 	SecondBound secondBound;
 public:
-	typedef typename Caller::result_type result_type;
-	typedef typename Caller::first_argument_type first_argument_type;
 	BindArguments2( FirstBound firstBound, SecondBound secondBound )
 		: firstBound( firstBound ), secondBound( secondBound ){
 	}
-	result_type operator()( first_argument_type firstArgument ) const {
+	get_result_type<Caller> operator()( get_argument<Caller, 0> firstArgument ) const {
 		return Caller::call( firstArgument, firstBound, secondBound );
 	}
 };
diff --git a/radiant/dialog.h b/radiant/dialog.h
index 19f680ad..d25224ad 100644
--- a/radiant/dialog.h
+++ b/radiant/dialog.h
@@ -23,13 +23,11 @@
 
 #include <list>
 
+#include "generic/callback.h"
 #include "gtkutil/dialog.h"
 #include "generic/callback.h"
 #include "string/string.h"
 
-template<typename Environment, typename FirstArgument, void( *func ) ( Environment&, FirstArgument )>
-class ReferenceCaller1;
-
 inline void BoolImport( bool& self, bool value ){
 	self = value;
 }
diff --git a/radiant/renderstate.cpp b/radiant/renderstate.cpp
index 5e071be8..2cd129b9 100644
--- a/radiant/renderstate.cpp
+++ b/radiant/renderstate.cpp
@@ -585,7 +585,7 @@ class OpenGLStateBucketAdd
 	const OpenGLRenderable& m_renderable;
 	const Matrix4& m_modelview;
 public:
-	typedef const RendererLight& first_argument_type;
+	using func = void(const RendererLight&);
 
 	OpenGLStateBucketAdd( OpenGLStateBucket& bucket, const OpenGLRenderable& renderable, const Matrix4& modelview ) :
 		m_bucket( bucket ), m_renderable( renderable ), m_modelview( modelview ){
@@ -599,7 +599,7 @@ class CountLights
 {
 	std::size_t m_count;
 public:
-	typedef const RendererLight& first_argument_type;
+	using func = void(RendererLight&);
 
 	CountLights() : m_count( 0 ){
 	}
diff --git a/radiant/selection.cpp b/radiant/selection.cpp
index af90e5ff..13b9ec4a 100644
--- a/radiant/selection.cpp
+++ b/radiant/selection.cpp
@@ -3438,7 +3438,7 @@ class ResizeTranslatable : public Translatable
 class SelectionCounter
 {
 public:
-	typedef const Selectable& first_argument_type;
+	using func = void(const Selectable &);
 
 	SelectionCounter( const SelectionChangeCallback& onchanged )
 		: m_count( 0 ), m_onchanged( onchanged ){
diff --git a/radiant/texwindow.cpp b/radiant/texwindow.cpp
index 5cfdf044..8fcce70a 100644
--- a/radiant/texwindow.cpp
+++ b/radiant/texwindow.cpp
@@ -656,7 +656,7 @@ class TextureCategoryLoadShader
 	const char* m_directory;
 	std::size_t& m_count;
 public:
-	typedef const char* first_argument_type;
+	using func = void(const char *);
 
 	TextureCategoryLoadShader( const char* directory, std::size_t& count )
 		: m_directory( directory ), m_count( count ){