HLMetaModOfficial/core/sourcehook/FastDelegate.h

//						FastDelegate.h
//	Efficient delegates in C++ that generate only two lines of asm code!
//  Documentation is found at http://www.codeproject.com/cpp/FastDelegate.asp
//
//						- Don Clugston, Mar 2004.
//		Major contributions were made by Jody Hagins.
// History:
// 24-Apr-04 1.0  * Submitted to CodeProject.
// 28-Apr-04 1.1  * Prevent most unsafe uses of evil static function hack.
//				  * Improved syntax for horrible_cast (thanks Paul Bludov).
//				  * Tested on Metrowerks MWCC and Intel ICL (IA32)
//				  * Compiled, but not run, on Comeau C++ and Intel Itanium ICL.
//	27-Jun-04 1.2 * Now works on Borland C++ Builder 5.5
//				  * Now works on /clr "managed C++" code on VC7, VC7.1
//				  * Comeau C++ now compiles without warnings.
//				  * Prevent the virtual inheritance case from being used on
//					  VC6 and earlier, which generate incorrect code.
//				  * Improved warning and error messages. Non-standard hacks
//					 now have compile-time checks to make them safer.
//				  * implicit_cast used instead of static_cast in many cases.
//				  * If calling a const member function, a const class pointer can be used.
//				  * MakeDelegate() global helper function added to simplify pass-by-value.
//				  * Added fastdelegate.clear()
// 16-Jul-04 1.2.1* Workaround for gcc bug (const member function pointers in templates)
// 30-Oct-04 1.3  * Support for (non-void) return values.
//				  * No more workarounds in client code!
//					 MSVC and Intel now use a clever hack invented by John Dlugosz:
//				     - The FASTDELEGATEDECLARE workaround is no longer necessary.
//					 - No more warning messages for VC6
//				  * Less use of macros. Error messages should be more comprehensible.
//				  * Added include guards
//				  * Added FastDelegate::empty() to test if invocation is safe (Thanks Neville Franks).
//				  * Now tested on VS 2005 Express Beta, PGI C++
// 24-Dec-04 1.4  * Added DelegateMemento, to allow collections of disparate delegates.
//                * <,>,<=,>= comparison operators to allow storage in ordered containers.
//				  * Substantial reduction of code size, especially the 'Closure' class.
//				  * Standardised all the compiler-specific workarounds.
//                * MFP conversion now works for CodePlay (but not yet supported in the full code).
//                * Now compiles without warnings on _any_ supported compiler, including BCC 5.5.1
//				  * New syntax: FastDelegate< int (char *, double) >.
// 14-Feb-05 1.4.1* Now treats =0 as equivalent to .clear(), ==0 as equivalent to .empty(). (Thanks elfric).
//				  * Now tested on Intel ICL for AMD64, VS2005 Beta for AMD64 and Itanium.
// 30-Mar-05 1.5  * Safebool idiom: "if (dg)" is now equivalent to "if (!dg.empty())"
//				  * Fully supported by CodePlay VectorC
//                * Bugfix for Metrowerks: empty() was buggy because a valid MFP can be 0 on MWCC!
//                * More optimal assignment,== and != operators for static function pointers.
//
// AlliedModders LLC modifications.
//
// 24-Oct-15 1.6  * Use C++11 variadic templates.
//

#ifndef FASTDELEGATE_H
#define FASTDELEGATE_H

#ifdef _MSC_VER
# if _MSC_VER > 1000
#  pragma once
# endif // _MSC_VER > 1000
#endif // #ifdef _MSC_VER

#include <memory.h> // to allow <,> comparisons

////////////////////////////////////////////////////////////////////////////////
//						Configuration options
//
////////////////////////////////////////////////////////////////////////////////

// Uncomment the following #define for optimally-sized delegates.
// In this case, the generated asm code is almost identical to the code you'd get
// if the compiler had native support for delegates.
// It will not work on systems where sizeof(dataptr) < sizeof(codeptr).
// Thus, it will not work for DOS compilers using the medium model.
// It will also probably fail on some DSP systems.
#define FASTDELEGATE_USESTATICFUNCTIONHACK

// Uncomment the next line to allow function declarator syntax.
// It is automatically enabled for those compilers where it is known to work.
//#define FASTDELEGATE_ALLOW_FUNCTION_TYPE_SYNTAX

////////////////////////////////////////////////////////////////////////////////
//						Compiler identification for workarounds
//
////////////////////////////////////////////////////////////////////////////////

// Compiler identification. It's not easy to identify Visual C++ because
// many vendors fraudulently define Microsoft's identifiers.
#if defined(_MSC_VER) && !defined(__MWERKS__) && !defined(__VECTOR_C) && !defined(__ICL) && !defined(__BORLANDC__)
#define FASTDLGT_ISMSVC

#if (_MSC_VER <1300) // Many workarounds are required for VC6.
#define FASTDLGT_VC6
#pragma warning(disable:4786) // disable this ridiculous warning
#endif

#endif

// Does the compiler uses Microsoft's member function pointer structure?
// If so, it needs special treatment.
// Metrowerks CodeWarrior, Intel, and CodePlay fraudulently define Microsoft's
// identifier, _MSC_VER. We need to filter Metrowerks out.
#if defined(_MSC_VER) && !defined(__MWERKS__)
#define FASTDLGT_MICROSOFT_MFP

#if !defined(__VECTOR_C)
// CodePlay doesn't have the __single/multi/virtual_inheritance keywords
#define FASTDLGT_HASINHERITANCE_KEYWORDS
#endif
#endif

// Does it allow function declarator syntax? The following compilers are known to work:
#if defined(FASTDLGT_ISMSVC) && (_MSC_VER >=1310) // VC 7.1
#define FASTDELEGATE_ALLOW_FUNCTION_TYPE_SYNTAX
#endif

// Gcc(2.95+), and versions of Digital Mars, Intel and Comeau in common use.
#if defined (__DMC__) || defined(__GNUC__) || defined(__ICL) || defined(__COMO__)
#define FASTDELEGATE_ALLOW_FUNCTION_TYPE_SYNTAX
#endif

// It works on Metrowerks MWCC 3.2.2. From boost.Config it should work on earlier ones too.
#if defined (__MWERKS__)
#define FASTDELEGATE_ALLOW_FUNCTION_TYPE_SYNTAX
#endif

#ifdef __GNUC__ // Workaround GCC bug #8271
	// At present, GCC doesn't recognize constness of MFPs in templates
#define FASTDELEGATE_GCC_BUG_8271
#endif



////////////////////////////////////////////////////////////////////////////////
//						General tricks used in this code
//
// (a) Error messages are generated by typdefing an array of negative size to
//     generate compile-time errors.
// (b) Warning messages on MSVC are generated by declaring unused variables, and
//	    enabling the "variable XXX is never used" warning.
// (c) Unions are used in a few compiler-specific cases to perform illegal casts.
// (d) For Microsoft and Intel, when adjusting the 'this' pointer, it's cast to
//     (char *) first to ensure that the correct number of *bytes* are added.
//
////////////////////////////////////////////////////////////////////////////////
//						Helper templates
//
////////////////////////////////////////////////////////////////////////////////


namespace fastdelegate {
namespace detail {	// we'll hide the implementation details in a nested namespace.

//		implicit_cast< >
// I believe this was originally going to be in the C++ standard but
// was left out by accident. It's even milder than static_cast.
// I use it instead of static_cast<> to emphasize that I'm not doing
// anything nasty.
// Usage is identical to static_cast<>
template <class OutputClass, class InputClass>
inline OutputClass implicit_cast(InputClass input){
	return input;
}

//		horrible_cast< >
// This is truly evil. It completely subverts C++'s type system, allowing you
// to cast from any class to any other class. Technically, using a union
// to perform the cast is undefined behaviour (even in C). But we can see if
// it is OK by checking that the union is the same size as each of its members.
// horrible_cast<> should only be used for compiler-specific workarounds.
// Usage is identical to reinterpret_cast<>.

// This union is declared outside the horrible_cast because BCC 5.5.1
// can't inline a function with a nested class, and gives a warning.
template <class OutputClass, class InputClass>
union horrible_union{
	OutputClass out;
	InputClass in;
};

template <class OutputClass, class InputClass>
inline OutputClass horrible_cast(const InputClass input){
	horrible_union<OutputClass, InputClass> u;
	// Cause a compile-time error if in, out and u are not the same size.
	// If the compile fails here, it means the compiler has peculiar
	// unions which would prevent the cast from working.
	static_assert(sizeof(InputClass)==sizeof(u) && sizeof(InputClass)==sizeof(OutputClass),
			"Can't use horrible cast");
	u.in = input;
	return u.out;
}

////////////////////////////////////////////////////////////////////////////////
//						Workarounds
//
////////////////////////////////////////////////////////////////////////////////

// Backwards compatibility: This macro used to be necessary in the virtual inheritance
// case for Intel and Microsoft. Now it just forward-declares the class.
#define FASTDELEGATEDECLARE(CLASSNAME)	class CLASSNAME;

// Prevent use of the static function hack with the DOS medium model.
#ifdef __MEDIUM__
#undef FASTDELEGATE_USESTATICFUNCTIONHACK
#endif

//			DefaultVoid - a workaround for 'void' templates in VC6.
//
//  (1) VC6 and earlier do not allow 'void' as a default template argument.
//  (2) They also doesn't allow you to return 'void' from a function.
//
// Workaround for (1): Declare a dummy type 'DefaultVoid' which we use
//   when we'd like to use 'void'. We convert it into 'void' and back
//   using the templates DefaultVoidToVoid<> and VoidToDefaultVoid<>.
// Workaround for (2): On VC6, the code for calling a void function is
//   identical to the code for calling a non-void function in which the
//   return value is never used, provided the return value is returned
//   in the EAX register, rather than on the stack.
//   This is true for most fundamental types such as int, enum, void *.
//   Const void * is the safest option since it doesn't participate
//   in any automatic conversions. But on a 16-bit compiler it might
//   cause extra code to be generated, so we disable it for all compilers
//   except for VC6 (and VC5).
#ifdef FASTDLGT_VC6
// VC6 workaround
typedef const void * DefaultVoid;
#else
// On any other compiler, just use a normal void.
typedef void DefaultVoid;
#endif

// Translate from 'DefaultVoid' to 'void'.
// Everything else is unchanged
template <class T>
struct DefaultVoidToVoid { typedef T type; };

template <>
struct DefaultVoidToVoid<DefaultVoid> {	typedef void type; };

// Translate from 'void' into 'DefaultVoid'
// Everything else is unchanged
template <class T>
struct VoidToDefaultVoid { typedef T type; };

template <>
struct VoidToDefaultVoid<void> { typedef DefaultVoid type; };



////////////////////////////////////////////////////////////////////////////////
//						Fast Delegates, part 1:
//
//		Conversion of member function pointer to a standard form
//
////////////////////////////////////////////////////////////////////////////////

// GenericClass is a fake class, ONLY used to provide a type.
// It is vitally important that it is never defined, so that the compiler doesn't
// think it can optimize the invocation. For example, Borland generates simpler
// code if it knows the class only uses single inheritance.

// Compilers using Microsoft's structure need to be treated as a special case.
#ifdef  FASTDLGT_MICROSOFT_MFP

#ifdef FASTDLGT_HASINHERITANCE_KEYWORDS
	// For Microsoft and Intel, we want to ensure that it's the most efficient type of MFP
	// (4 bytes), even when the /vmg option is used. Declaring an empty class
	// would give 16 byte pointers in this case....
	class __single_inheritance GenericClass;
#endif
	// ...but for Codeplay, an empty class *always* gives 4 byte pointers.
	// If compiled with the /clr option ("managed C++"), the JIT compiler thinks
	// it needs to load GenericClass before it can call any of its functions,
	// (compiles OK but crashes at runtime!), so we need to declare an
	// empty class to make it happy.
	// Codeplay and VC4 can't cope with the unknown_inheritance case either.
	class GenericClass {};
#else
	class GenericClass;
#endif

// The size of a single inheritance member function pointer.
const int SINGLE_MEMFUNCPTR_SIZE = sizeof(void (GenericClass::*)());

//						SimplifyMemFunc< >::Convert()
//
//	A template function that converts an arbitrary member function pointer into the
//	simplest possible form of member function pointer, using a supplied 'this' pointer.
//  According to the standard, this can be done legally with reinterpret_cast<>.
//	For (non-standard) compilers which use member function pointers which vary in size
//  depending on the class, we need to use	knowledge of the internal structure of a
//  member function pointer, as used by the compiler. Template specialization is used
//  to distinguish between the sizes. Because some compilers don't support partial
//	template specialisation, I use full specialisation of a wrapper struct.

// general case -- don't know how to convert it. Force a compile failure
template <int N>
struct SimplifyMemFunc {
	template <class X, class XFuncType, class GenericMemFuncType>
	inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
		GenericMemFuncType &bound_func) {
		// Unsupported member function type -- force a compile failure.
		static_assert(N >= 100, "Unsupported memeber function pointer on this compiler");
		return 0;
	}
};

// For compilers where all member func ptrs are the same size, everything goes here.
// For non-standard compilers, only single_inheritance classes go here.
template <>
struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE>  {
	template <class X, class XFuncType, class GenericMemFuncType>
	inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
#if defined __DMC__
		// Digital Mars doesn't allow you to cast between abitrary PMF's,
		// even though the standard says you can. The 32-bit compiler lets you
		// static_cast through an int, but the DOS compiler doesn't.
		bound_func = horrible_cast<GenericMemFuncType>(function_to_bind);
#else
        bound_func = reinterpret_cast<GenericMemFuncType>(function_to_bind);
#endif
        return reinterpret_cast<GenericClass *>(pthis);
	}
};

////////////////////////////////////////////////////////////////////////////////
//						Fast Delegates, part 1b:
//
//					Workarounds for Microsoft and Intel
//
////////////////////////////////////////////////////////////////////////////////


// Compilers with member function pointers which violate the standard (MSVC, Intel, Codeplay),
// need to be treated as a special case.
#ifdef FASTDLGT_MICROSOFT_MFP

// We use unions to perform horrible_casts. I would like to use #pragma pack(push, 1)
// at the start of each function for extra safety, but VC6 seems to ICE
// intermittently if you do this inside a template.

// __multiple_inheritance classes go here
// Nasty hack for Microsoft and Intel (IA32 and Itanium)
template<>
struct SimplifyMemFunc< SINGLE_MEMFUNCPTR_SIZE + sizeof(int) >  {
	template <class X, class XFuncType, class GenericMemFuncType>
	inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
		GenericMemFuncType &bound_func) {
		// We need to use a horrible_cast to do this conversion.
		// In MSVC, a multiple inheritance member pointer is internally defined as:
        union {
			XFuncType func;
			struct {
				GenericMemFuncType funcaddress; // points to the actual member function
				int delta;	     // #BYTES to be added to the 'this' pointer
			}s;
        } u;
		// Check that the horrible_cast will work
		static_assert(sizeof(function_to_bind)==sizeof(u.s), "Can't use horrible cast");
        u.func = function_to_bind;
		bound_func = u.s.funcaddress;
		return reinterpret_cast<GenericClass *>(reinterpret_cast<char *>(pthis) + u.s.delta);
	}
};

// virtual inheritance is a real nuisance. It's inefficient and complicated.
// On MSVC and Intel, there isn't enough information in the pointer itself to
// enable conversion to a closure pointer. Earlier versions of this code didn't
// work for all cases, and generated a compile-time error instead.
// But a very clever hack invented by John M. Dlugosz solves this problem.
// My code is somewhat different to his: I have no asm code, and I make no
// assumptions about the calling convention that is used.

// In VC++ and ICL, a virtual_inheritance member pointer
// is internally defined as:
struct MicrosoftVirtualMFP {
	void (GenericClass::*codeptr)(); // points to the actual member function
	int delta;		// #bytes to be added to the 'this' pointer
	int vtable_index; // or 0 if no virtual inheritance
};
// The CRUCIAL feature of Microsoft/Intel MFPs which we exploit is that the
// m_codeptr member is *always* called, regardless of the values of the other
// members. (This is *not* true for other compilers, eg GCC, which obtain the
// function address from the vtable if a virtual function is being called).
// Dlugosz's trick is to make the codeptr point to a probe function which
// returns the 'this' pointer that was used.

// Define a generic class that uses virtual inheritance.
// It has a trival member function that returns the value of the 'this' pointer.
struct GenericVirtualClass : virtual public GenericClass
{
	typedef GenericVirtualClass * (GenericVirtualClass::*ProbePtrType)();
	GenericVirtualClass * GetThis() { return this; }
};

// __virtual_inheritance classes go here
template <>
struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE + 2*sizeof(int) >
{

	template <class X, class XFuncType, class GenericMemFuncType>
	inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
		GenericMemFuncType &bound_func) {
		union {
			XFuncType func;
			GenericClass* (X::*ProbeFunc)();
			MicrosoftVirtualMFP s;
		} u;
		u.func = function_to_bind;
		bound_func = reinterpret_cast<GenericMemFuncType>(u.s.codeptr);
		union {
			GenericVirtualClass::ProbePtrType virtfunc;
			MicrosoftVirtualMFP s;
		} u2;
		// Check that the horrible_cast<>s will work
		static_assert(sizeof(function_to_bind)==sizeof(u.s)
			&& sizeof(function_to_bind)==sizeof(u.ProbeFunc)
			&& sizeof(u2.virtfunc)==sizeof(u2.s),
			"Can't use horrible cast.");
   // Unfortunately, taking the address of a MF prevents it from being inlined, so
   // this next line can't be completely optimised away by the compiler.
		u2.virtfunc = &GenericVirtualClass::GetThis;
		u.s.codeptr = u2.s.codeptr;
		return (pthis->*u.ProbeFunc)();
	}
};

#if (_MSC_VER <1300)

// Nasty hack for Microsoft Visual C++ 6.0
// unknown_inheritance classes go here
// There is a compiler bug in MSVC6 which generates incorrect code in this case!!
template <>
struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE + 3*sizeof(int) >
{
	template <class X, class XFuncType, class GenericMemFuncType>
	inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
		GenericMemFuncType &bound_func) {
		// There is an apalling but obscure compiler bug in MSVC6 and earlier:
		// vtable_index and 'vtordisp' are always set to 0 in the
		// unknown_inheritance case!
		// This means that an incorrect function could be called!!!
		// Compiling with the /vmg option leads to potentially incorrect code.
		// This is probably the reason that the IDE has a user interface for specifying
		// the /vmg option, but it is disabled -  you can only specify /vmg on
		// the command line. In VC1.5 and earlier, the compiler would ICE if it ever
		// encountered this situation.
		// It is OK to use the /vmg option if /vmm or /vms is specified.

		// Fortunately, the wrong function is only called in very obscure cases.
		// It only occurs when a derived class overrides a virtual function declared
		// in a virtual base class, and the member function
		// points to the *Derived* version of that function. The problem can be
		// completely averted in 100% of cases by using the *Base class* for the
		// member fpointer. Ie, if you use the base class as an interface, you'll
		// stay out of trouble.
		// Occasionally, you might want to point directly to a derived class function
		// that isn't an override of a base class. In this case, both vtable_index
		// and 'vtordisp' are zero, but a virtual_inheritance pointer will be generated.
		// We can generate correct code in this case. To prevent an incorrect call from
		// ever being made, on MSVC6 we generate a warning, and call a function to
		// make the program crash instantly.
		static_assert(true, "VC6 Compiler Bug");
		return 0;
	}
};


#else

// Nasty hack for Microsoft and Intel (IA32 and Itanium)
// unknown_inheritance classes go here
// This is probably the ugliest bit of code I've ever written. Look at the casts!
// There is a compiler bug in MSVC6 which prevents it from using this code.
template <>
struct SimplifyMemFunc<SINGLE_MEMFUNCPTR_SIZE + 3*sizeof(int) >
{
	template <class X, class XFuncType, class GenericMemFuncType>
	inline static GenericClass *Convert(X *pthis, XFuncType function_to_bind,
			GenericMemFuncType &bound_func) {
		// The member function pointer is 16 bytes long. We can't use a normal cast, but
		// we can use a union to do the conversion.
		union {
			XFuncType func;
			// In VC++ and ICL, an unknown_inheritance member pointer
			// is internally defined as:
			struct {
				GenericMemFuncType m_funcaddress; // points to the actual member function
				int delta;		// #bytes to be added to the 'this' pointer
				int vtordisp;		// #bytes to add to 'this' to find the vtable
				int vtable_index; // or 0 if no virtual inheritance
			} s;
		} u;
		// Check that the horrible_cast will work
		static_assert(sizeof(XFuncType)==sizeof(u.s), "Can't use horrible cast.");
		u.func = function_to_bind;
		bound_func = u.s.funcaddress;
		int virtual_delta = 0;
		if (u.s.vtable_index) { // Virtual inheritance is used
			// First, get to the vtable.
			// It is 'vtordisp' bytes from the start of the class.
			const int * vtable = *reinterpret_cast<const int *const*>(
				reinterpret_cast<const char *>(pthis) + u.s.vtordisp );

			// 'vtable_index' tells us where in the table we should be looking.
			virtual_delta = u.s.vtordisp + *reinterpret_cast<const int *>(
				reinterpret_cast<const char *>(vtable) + u.s.vtable_index);
		}
		// The int at 'virtual_delta' gives us the amount to add to 'this'.
        // Finally we can add the three components together. Phew!
        return reinterpret_cast<GenericClass *>(
			reinterpret_cast<char *>(pthis) + u.s.delta + virtual_delta);
	};
};
#endif // MSVC 7 and greater

#endif // MS/Intel hacks

}  // namespace detail

////////////////////////////////////////////////////////////////////////////////
//						Fast Delegates, part 2:
//
//	Define the delegate storage, and cope with static functions
//
////////////////////////////////////////////////////////////////////////////////

// DelegateMemento -- an opaque structure which can hold an arbitary delegate.
// It knows nothing about the calling convention or number of arguments used by
// the function pointed to.
// It supplies comparison operators so that it can be stored in STL collections.
// It cannot be set to anything other than null, nor invoked directly:
//   it must be converted to a specific delegate.

// Implementation:
// There are two possible implementations: the Safe method and the Evil method.
//				DelegateMemento - Safe version
//
// This implementation is standard-compliant, but a bit tricky.
// A static function pointer is stored inside the class.
// Here are the valid values:
// +-- Static pointer --+--pThis --+-- pMemFunc-+-- Meaning------+
// |   0				|  0       |   0        | Empty          |
// |   !=0              |(dontcare)|  Invoker   | Static function|
// |   0                |  !=0     |  !=0*      | Method call    |
// +--------------------+----------+------------+----------------+
//  * For Metrowerks, this can be 0. (first virtual function in a 
//       single_inheritance class).
// When stored stored inside a specific delegate, the 'dontcare' entries are replaced
// with a reference to the delegate itself. This complicates the = and == operators
// for the delegate class.

//				DelegateMemento - Evil version
//
// For compilers where data pointers are at least as big as code pointers, it is
// possible to store the function pointer in the this pointer, using another
// horrible_cast. In this case the DelegateMemento implementation is simple:
// +--pThis --+-- pMemFunc-+-- Meaning---------------------+
// |    0     |  0         | Empty                         |
// |  !=0     |  !=0*      | Static function or method call|
// +----------+------------+-------------------------------+
//  * For Metrowerks, this can be 0. (first virtual function in a 
//       single_inheritance class).
// Note that the Sun C++ and MSVC documentation explicitly state that they 
// support static_cast between void * and function pointers.

class DelegateMemento {
protected:
	// the data is protected, not private, because many
	// compilers have problems with template friends.
	typedef void (detail::GenericClass::*GenericMemFuncType)(); // arbitrary MFP.
	detail::GenericClass *m_pthis;
	GenericMemFuncType m_pFunction;

#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
	typedef void (*GenericFuncPtr)(); // arbitrary code pointer
	GenericFuncPtr m_pStaticFunction;
#endif

public:
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
	DelegateMemento() : m_pthis(0), m_pFunction(0), m_pStaticFunction(0) {};
	void clear() {
		m_pthis=0; m_pFunction=0; m_pStaticFunction=0;
	}
#else
	DelegateMemento() : m_pthis(0), m_pFunction(0) {};
	void clear() {	m_pthis=0; m_pFunction=0;	}
#endif
public:
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
	inline bool IsEqual (const DelegateMemento &x) const{
	    // We have to cope with the static function pointers as a special case
		if (m_pFunction!=x.m_pFunction) return false;
		// the static function ptrs must either both be equal, or both be 0.
		if (m_pStaticFunction!=x.m_pStaticFunction) return false;
		if (m_pStaticFunction!=0) return m_pthis==x.m_pthis;
		else return true;
	}
#else // Evil Method
	inline bool IsEqual (const DelegateMemento &x) const{
		return m_pthis==x.m_pthis && m_pFunction==x.m_pFunction;
	}
#endif
	// Provide a strict weak ordering for DelegateMementos.
	inline bool IsLess(const DelegateMemento &right) const {
		// deal with static function pointers first
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		if (m_pStaticFunction !=0 || right.m_pStaticFunction!=0)
				return m_pStaticFunction < right.m_pStaticFunction;
#endif
		if (m_pthis !=right.m_pthis) return m_pthis < right.m_pthis;
	// There are no ordering operators for member function pointers,
	// but we can fake one by comparing each byte. The resulting ordering is
	// arbitrary (and compiler-dependent), but it permits storage in ordered STL containers.
		return memcmp(&m_pFunction, &right.m_pFunction, sizeof(m_pFunction)) < 0;

	}
	// BUGFIX (Mar 2005):
	// We can't just compare m_pFunction because on Metrowerks,
	// m_pFunction can be zero even if the delegate is not empty!
	inline bool operator ! () const		// Is it bound to anything?
	{ return m_pthis==0 && m_pFunction==0; }
	inline bool empty() const		// Is it bound to anything?
	{ return m_pthis==0 && m_pFunction==0; }
public:
	DelegateMemento & operator = (const DelegateMemento &right)  {
		SetMementoFrom(right);
		return *this;
	}
	inline bool operator <(const DelegateMemento &right) {
		return IsLess(right);
	}
	inline bool operator >(const DelegateMemento &right) {
		return right.IsLess(*this);
	}
	DelegateMemento (const DelegateMemento &right)  :
		m_pthis(right.m_pthis), m_pFunction(right.m_pFunction)
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		, m_pStaticFunction (right.m_pStaticFunction)
#endif
		{}
protected:
	void SetMementoFrom(const DelegateMemento &right)  {
		m_pFunction = right.m_pFunction;
		m_pthis = right.m_pthis;
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		m_pStaticFunction = right.m_pStaticFunction;
#endif
	}
};


//						ClosurePtr<>
//
// A private wrapper class that adds function signatures to DelegateMemento.
// It's the class that does most of the actual work.
// The signatures are specified by:
// GenericMemFunc: must be a type of GenericClass member function pointer.
// StaticFuncPtr:  must be a type of function pointer with the same signature
//                 as GenericMemFunc.
// UnvoidStaticFuncPtr: is the same as StaticFuncPtr, except on VC6
//                 where it never returns void (returns DefaultVoid instead).

// An outer class, FastDelegateN<>, handles the invoking and creates the
// necessary typedefs.
// This class does everything else.

namespace detail {

template < class GenericMemFunc, class StaticFuncPtr, class UnvoidStaticFuncPtr>
class ClosurePtr : public DelegateMemento {
public:
	// These functions are for setting the delegate to a member function.

	// Here's the clever bit: we convert an arbitrary member function into a
	// standard form. XMemFunc should be a member function of class X, but I can't
	// enforce that here. It needs to be enforced by the wrapper class.
	template < class X, class XMemFunc >
	inline void bindmemfunc(X *pthis, XMemFunc function_to_bind ) {
		m_pthis = SimplifyMemFunc< sizeof(function_to_bind) >
			::Convert(pthis, function_to_bind, m_pFunction);
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		m_pStaticFunction = 0;
#endif
	}
	// For const member functions, we only need a const class pointer.
	// Since we know that the member function is const, it's safe to
	// remove the const qualifier from the 'this' pointer with a const_cast.
	// VC6 has problems if we just overload 'bindmemfunc', so we give it a different name.
	template < class X, class XMemFunc>
	inline void bindconstmemfunc(const X *pthis, XMemFunc function_to_bind) {
		m_pthis= SimplifyMemFunc< sizeof(function_to_bind) >
			::Convert(const_cast<X*>(pthis), function_to_bind, m_pFunction);
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		m_pStaticFunction = 0;
#endif
	}
#ifdef FASTDELEGATE_GCC_BUG_8271	// At present, GCC doesn't recognize constness of MFPs in templates
	template < class X, class XMemFunc>
	inline void bindmemfunc(const X *pthis, XMemFunc function_to_bind) {
		bindconstmemfunc(pthis, function_to_bind);
#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)
		m_pStaticFunction = 0;
#endif
	}
#endif
	// These functions are required for invoking the stored function
	inline GenericClass *GetClosureThis() const { return m_pthis; }
	inline GenericMemFunc GetClosureMemPtr() const { return reinterpret_cast<GenericMemFunc>(m_pFunction); }

// There are a few ways of dealing with static function pointers.
// There's a standard-compliant, but tricky method.
// There's also a straightforward hack, that won't work on DOS compilers using the
// medium memory model. It's so evil that I can't recommend it, but I've
// implemented it anyway because it produces very nice asm code.

#if !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)

//				ClosurePtr<> - Safe version
//
// This implementation is standard-compliant, but a bit tricky.
// I store the function pointer inside the class, and the delegate then
// points to itself. Whenever the delegate is copied, these self-references
// must be transformed, and this complicates the = and == operators.
public:
	// The next two functions are for operator ==, =, and the copy constructor.
	// We may need to convert the m_pthis pointers, so that
	// they remain as self-references.
	template< class DerivedClass >
	inline void CopyFrom (DerivedClass *pParent, const DelegateMemento &x) {
		SetMementoFrom(x);
		if (m_pStaticFunction!=0) {
			// transform self references...
			m_pthis=reinterpret_cast<GenericClass *>(pParent);
		}
	}
	// For static functions, the 'static_function_invoker' class in the parent
	// will be called. The parent then needs to call GetStaticFunction() to find out
	// the actual function to invoke.
	template < class DerivedClass, class ParentInvokerSig >
	inline void bindstaticfunc(DerivedClass *pParent, ParentInvokerSig static_function_invoker,
				StaticFuncPtr function_to_bind ) {
		if (function_to_bind==0) { // cope with assignment to 0
			m_pFunction=0;
		} else {
			bindmemfunc(pParent, static_function_invoker);
        }
		m_pStaticFunction=reinterpret_cast<GenericFuncPtr>(function_to_bind);
	}
	inline UnvoidStaticFuncPtr GetStaticFunction() const {
		return reinterpret_cast<UnvoidStaticFuncPtr>(m_pStaticFunction);
	}
#else

//				ClosurePtr<> - Evil version
//
// For compilers where data pointers are at least as big as code pointers, it is
// possible to store the function pointer in the this pointer, using another
// horrible_cast. Invocation isn't any faster, but it saves 4 bytes, and
// speeds up comparison and assignment. If C++ provided direct language support
// for delegates, they would produce asm code that was almost identical to this.
// Note that the Sun C++ and MSVC documentation explicitly state that they
// support static_cast between void * and function pointers.

	template< class DerivedClass >
	inline void CopyFrom (DerivedClass *pParent, const DelegateMemento &right) {
		SetMementoFrom(right);
	}
	// For static functions, the 'static_function_invoker' class in the parent
	// will be called. The parent then needs to call GetStaticFunction() to find out
	// the actual function to invoke.
	// ******** EVIL, EVIL CODE! *******
	template < 	class DerivedClass, class ParentInvokerSig>
	inline void bindstaticfunc(DerivedClass *pParent, ParentInvokerSig static_function_invoker,
				StaticFuncPtr function_to_bind) {
		if (function_to_bind==0) { // cope with assignment to 0
			m_pFunction=0;
		} else { 
		   // We'll be ignoring the 'this' pointer, but we need to make sure we pass
		   // a valid value to bindmemfunc().
			bindmemfunc(pParent, static_function_invoker);
        }

		// WARNING! Evil hack. We store the function in the 'this' pointer!
		// Ensure that there's a compilation failure if function pointers
		// and data pointers have different sizes.
		// If you get this error, you need to #undef FASTDELEGATE_USESTATICFUNCTIONHACK.
		static_assert(sizeof(GenericClass *)==sizeof(function_to_bind), "Can't use evil method.");
		m_pthis = horrible_cast<GenericClass *>(function_to_bind);
		// MSVC, SunC++ and DMC accept the following (non-standard) code:
//		m_pthis = static_cast<GenericClass *>(static_cast<void *>(function_to_bind));
		// BCC32, Comeau and DMC accept this method. MSVC7.1 needs __int64 instead of long
//		m_pthis = reinterpret_cast<GenericClass *>(reinterpret_cast<long>(function_to_bind));
	}
	// ******** EVIL, EVIL CODE! *******
	// This function will be called with an invalid 'this' pointer!!
	// We're just returning the 'this' pointer, converted into
	// a function pointer!
	inline UnvoidStaticFuncPtr GetStaticFunction() const {
		// Ensure that there's a compilation failure if function pointers
		// and data pointers have different sizes.
		// If you get this error, you need to #undef FASTDELEGATE_USESTATICFUNCTIONHACK.
		static_assert(sizeof(UnvoidStaticFuncPtr)==sizeof(this), "Can't use evil method.");
		return horrible_cast<UnvoidStaticFuncPtr>(this);
	}
#endif // !defined(FASTDELEGATE_USESTATICFUNCTIONHACK)

	// Does the closure contain this static function?
	inline bool IsEqualToStaticFuncPtr(StaticFuncPtr funcptr){
		if (funcptr==0) return empty();
	// For the Evil method, if it doesn't actually contain a static function, this will return an arbitrary
	// value that is not equal to any valid function pointer.
		else return funcptr==reinterpret_cast<StaticFuncPtr>(GetStaticFunction());
	}
};


} // namespace detail

////////////////////////////////////////////////////////////////////////////////
//						Fast Delegates, part 3:
//
//				Wrapper classes to ensure type safety
//
////////////////////////////////////////////////////////////////////////////////


// Once we have the member function conversion templates, it's easy to make the
// wrapper classes. So that they will work with as many compilers as possible,
// the classes are of the form
//   FastDelegate3<int, char *, double>
// They can cope with any combination of parameters. The max number of parameters
// allowed is 8, but it is trivial to increase this limit.
// Note that we need to treat const member functions seperately.
// All this class does is to enforce type safety, and invoke the delegate with
// the correct list of parameters.

// Because of the weird rule about the class of derived member function pointers,
// you sometimes need to apply a downcast to the 'this' pointer.
// This is the reason for the use of "implicit_cast<X*>(pthis)" in the code below.
// If CDerivedClass is derived from CBaseClass, but doesn't override SimpleVirtualFunction,
// without this trick you'd need to write:
//		MyDelegate(static_cast<CBaseClass *>(&d), &CDerivedClass::SimpleVirtualFunction);
// but with the trick you can write
//		MyDelegate(&d, &CDerivedClass::SimpleVirtualFunction);

// RetType is the type the compiler uses in compiling the template. For VC6,
// it cannot be void. DesiredRetType is the real type which is returned from
// all of the functions. It can be void.

// Implicit conversion to "bool" is achieved using the safe_bool idiom,
// using member data pointers (MDP). This allows "if (dg)..." syntax
// Because some compilers (eg codeplay) don't have a unique value for a zero
// MDP, an extra padding member is added to the SafeBool struct.
// Some compilers (eg VC6) won't implicitly convert from 0 to an MDP, so
// in that case the static function constructor is not made explicit; this
// allows "if (dg==0) ..." to compile.

template<class RetType, class ... Params>
class FastDelegate {
private:
	typedef typename detail::DefaultVoidToVoid<RetType>::type DesiredRetType;
	typedef DesiredRetType (*StaticFunctionPtr)(Params... params);
	typedef RetType (*UnvoidStaticFunctionPtr)(Params... params);
	typedef RetType (detail::GenericClass::*GenericMemFn)(Params... params);
	typedef detail::ClosurePtr<GenericMemFn, StaticFunctionPtr, UnvoidStaticFunctionPtr> ClosureType;
	ClosureType m_Closure;
public:
	// Typedefs to aid generic programming
	typedef FastDelegate type;

	// Construction and comparison functions
	FastDelegate() {
		clear();
	}
	FastDelegate(const FastDelegate &x) {
		m_Closure.CopyFrom(this, x.m_Closure);
	}
	void operator = (const FastDelegate &x)  {
		m_Closure.CopyFrom(this, x.m_Closure);
	}
	bool operator ==(const FastDelegate &x) const {
		return m_Closure.IsEqual(x.m_Closure);
	}
	bool operator !=(const FastDelegate &x) const {
		return !m_Closure.IsEqual(x.m_Closure);
	}
	bool operator <(const FastDelegate &x) const {
		return m_Closure.IsLess(x.m_Closure);
	}
	bool operator >(const FastDelegate &x) const {
		return x.m_Closure.IsLess(m_Closure);
	}
	// Binding to non-const member functions
	template < class X, class Y >
	FastDelegate(Y *pthis, DesiredRetType (X::* function_to_bind)(Params... params) ) {
		m_Closure.bindmemfunc(detail::implicit_cast<X*>(pthis), function_to_bind);
	}
	template < class X, class Y >
	inline void bind(Y *pthis, DesiredRetType (X::* function_to_bind)(Params... params)) {
		m_Closure.bindmemfunc(detail::implicit_cast<X*>(pthis), function_to_bind);
	}
	// Binding to const member functions.
	template < class X, class Y >
	FastDelegate(const Y *pthis, DesiredRetType (X::* function_to_bind)(Params... params) const) {
		m_Closure.bindconstmemfunc(detail::implicit_cast<const X*>(pthis), function_to_bind);
	}
	template < class X, class Y >
	inline void bind(const Y *pthis, DesiredRetType (X::* function_to_bind)(Params... params) const) {
		m_Closure.bindconstmemfunc(detail::implicit_cast<const X *>(pthis), function_to_bind);
	}
	// Static functions. We convert them into a member function call.
	// This constructor also provides implicit conversion
	FastDelegate(DesiredRetType (*function_to_bind)(Params... params) ) {
		bind(function_to_bind);
	}
	// for efficiency, prevent creation of a temporary
	void operator = (DesiredRetType (*function_to_bind)(Params... params) ) {
		bind(function_to_bind);
	}
	inline void bind(DesiredRetType (*function_to_bind)(Params... params)) {
		m_Closure.bindstaticfunc(this, &FastDelegate::InvokeStaticFunction, function_to_bind);
	}
	// Invoke the delegate
	RetType operator() (Params... params) const {
		return (m_Closure.GetClosureThis()->*(m_Closure.GetClosureMemPtr()))(params...);
	}
	// Implicit conversion to "bool" using the safe_bool idiom
private:
	typedef struct SafeBoolStruct {
		int a_data_pointer_to_this_is_0_on_buggy_compilers;
		StaticFunctionPtr m_nonzero;
	} UselessTypedef;
	typedef StaticFunctionPtr SafeBoolStruct::*unspecified_bool_type;
public:
	operator unspecified_bool_type() const {
		return empty() ? 0: &SafeBoolStruct::m_nonzero;
	}
	// necessary to allow ==0 to work despite the safe_bool idiom
	inline bool operator==(StaticFunctionPtr funcptr) {
		return m_Closure.IsEqualToStaticFuncPtr(funcptr);
	}
	inline bool operator!=(StaticFunctionPtr funcptr) { 
		return !m_Closure.IsEqualToStaticFuncPtr(funcptr);
	}
	inline bool operator ! () const	{	// Is it bound to anything?
		return !m_Closure;
	}
	inline bool empty() const {
		return !m_Closure;
	}
	void clear() {
		m_Closure.clear();
	}
	// Conversion to and from the DelegateMemento storage class
	const DelegateMemento & GetMemento() {
		return m_Closure;
	}
	void SetMemento(const DelegateMemento &any) {
		m_Closure.CopyFrom(this, any);
	}

private:
	// Invoker for static functions
	RetType InvokeStaticFunction(Params... params) const {
		return (*(m_Closure.GetStaticFunction()))(params...);
	}
};

////////////////////////////////////////////////////////////////////////////////
//						Fast Delegates, part 4:
//
//				FastDelegate<> class (Original author: Jody Hagins)
//	Allows boost::function style syntax like:
//			FastDelegate< double (int, long) >
// instead of:
//			FastDelegate2< int, long, double >
//
////////////////////////////////////////////////////////////////////////////////

#ifdef FASTDELEGATE_ALLOW_FUNCTION_TYPE_SYNTAX

//N=0
// Specialization to allow use of
// FastDelegate< R (  ) >
// instead of
// FastDelegate0 < R >
template<typename R, typename... Params>
class FastDelegate< R (Params...) >
  // Inherit from FastDelegate0 so that it can be treated just like a FastDelegate0
  : public FastDelegate < R, Params... >
{
public:
  // Make using the base type a bit easier via typedef.
  typedef FastDelegate < R, Params... > BaseType;

  // Allow users access to the specific type of this delegate.
  typedef FastDelegate SelfType;

  // Mimic the base class constructors.
  FastDelegate() : BaseType() { }

  template < class X, class Y >
  FastDelegate(Y * pthis,
    R (X::* function_to_bind)(Params... params))
    : BaseType(pthis, function_to_bind)  { }

  template < class X, class Y >
  FastDelegate(const Y *pthis,
      R (X::* function_to_bind)(Params... params) const)
    : BaseType(pthis, function_to_bind)
  {  }

  FastDelegate(R (*function_to_bind)(Params... params))
    : BaseType(function_to_bind)  { }
  void operator = (const BaseType &x)  {
		*static_cast<BaseType*>(this) = x; }
};

#endif //FASTDELEGATE_ALLOW_FUNCTION_TYPE_SYNTAX

////////////////////////////////////////////////////////////////////////////////
//						Fast Delegates, part 5:
//
//				MakeDelegate() helper function
//
//			MakeDelegate(&x, &X::func) returns a fastdelegate of the type
//			necessary for calling x.func() with the correct number of arguments.
//			This makes it possible to eliminate many typedefs from user code.
//
////////////////////////////////////////////////////////////////////////////////

// Also declare overloads of a MakeDelegate() global function to
// reduce the need for typedefs.
// We need seperate overloads for const and non-const member functions.
// Also, because of the weird rule about the class of derived member function pointers,
// implicit downcasts may need to be applied later to the 'this' pointer.
// That's why two classes (X and Y) appear in the definitions. Y must be implicitly
// castable to X.

// Workaround for VC6. VC6 needs void return types converted into DefaultVoid.
// GCC 3.2 and later won't compile this unless it's preceded by 'typename',
// but VC6 doesn't allow 'typename' in this context.
// So, I have to use a macro.

#ifdef FASTDLGT_VC6
#define FASTDLGT_RETTYPE detail::VoidToDefaultVoid<RetType>::type
#else
#define FASTDLGT_RETTYPE RetType
#endif

//N=1
template <class X, class Y, class RetType, class ... Params>
FastDelegate<FASTDLGT_RETTYPE, Params...> MakeDelegate(Y* x, RetType (X::*func)(Params... params)) {
	return FastDelegate<FASTDLGT_RETTYPE, Params...>(x, func);
}

template <class X, class Y, class RetType, class ... Params>
FastDelegate<FASTDLGT_RETTYPE, Params...> MakeDelegate(Y* x, RetType (X::*func)(Params... params) const) {
	return FastDelegate<FASTDLGT_RETTYPE, Params...>(x, func);
}

template <class RetType, class ... Params>
FastDelegate<FASTDLGT_RETTYPE, Params...> MakeDelegate(RetType (*func)(Params... params)) {
	return FastDelegate<FASTDLGT_RETTYPE, Params...>(func);
}

 // clean up after ourselves...
#undef FASTDLGT_RETTYPE

} // namespace fastdelegate

#endif // !defined(FASTDELEGATE_H)