/* Copyright 2003-2006 Joaquín M López Muñoz.

  * Distributed under the Boost Software License, Version 1.0.

  * (See accompanying file LICENSE_1_0.txt or copy at

  * http://www.boost.org/LICENSE_1_0.txt)

  *

  * See http://www.boost.org/libs/multi_index for library home page.

  */

 #ifndef BOOST_MULTI_INDEX_MEM_FUN_HPP

 #define BOOST_MULTI_INDEX_MEM_FUN_HPP

 #if defined(_MSC_VER)&&(_MSC_VER>=1200)

 #pragma once

 #endif

 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */

 #include <boost/mpl/if.hpp>

 #include <boost/type_traits/remove_reference.hpp>

 #include <boost/utility/enable_if.hpp>

 #if !defined(BOOST_NO_SFINAE)

 #include <boost/type_traits/is_convertible.hpp>

 #endif

 namespace boost{

 template<class T> class reference_wrapper; /* fwd decl. */

 namespace multi_index{

 /* mem_fun implements a read-only key extractor based on a given non-const

  * member function of a class.

  * const_mem_fun does the same for const member functions.

  * Additionally, mem_fun  and const_mem_fun are overloaded to support

  * referece_wrappers of T and "chained pointers" to T's. By chained pointer

  * to T we  mean a type P such that, given a p of Type P

  *   *...n...*x is convertible to T&, for some n>=1.

  * Examples of chained pointers are raw and smart pointers, iterators and

  * arbitrary combinations of these (vg. T** or auto_ptr<T*>.)

  */

 /* NB. Some overloads of operator() have an extra dummy parameter int=0.

  * This disambiguator serves several purposes:

  *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as

  *    specializations of a previous member function template.

  *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns

  *    as if they have the same signature.

  *  - If remove_const is broken due to lack of PTS, int=0 avoids the

  *    declaration of memfuns with identical signature.

  */

 template<class Class,typename Type,Type (Class::*PtrToMemberFunction)()const>

 struct const_mem_fun

 {

   typedef typename remove_reference<Type>::type result_type;

   template<typename ChainedPtr>

 #if !defined(BOOST_NO_SFINAE)

   typename disable_if<

     is_convertible<const ChainedPtr&,const Class&>,Type>::type

 #else

   Type

 #endif

   operator()(const ChainedPtr& x)const

   {

     return operator()(*x);

   }

   Type operator()(const Class& x)const

   {

     return (x.*PtrToMemberFunction)();

   }

   Type operator()(const reference_wrapper<const Class>& x)const

   { 

     return operator()(x.get());

   }

   Type operator()(const reference_wrapper<Class>& x,int=0)const

   { 

     return operator()(x.get());

   }

 };

 template<class Class,typename Type,Type (Class::*PtrToMemberFunction)()>

 struct mem_fun

 {

   typedef typename remove_reference<Type>::type result_type;

   template<typename ChainedPtr>

 #if !defined(BOOST_NO_SFINAE)

   typename disable_if<

     is_convertible<ChainedPtr&,Class&>,Type>::type

 #else

   Type

 #endif

   operator()(const ChainedPtr& x)const

   {

     return operator()(*x);

   }

   Type operator()(Class& x)const

   {

     return (x.*PtrToMemberFunction)();

   }

   Type operator()(const reference_wrapper<Class>& x)const

   { 

     return operator()(x.get());

   }

 };

 /* MSVC++ 6.0 has problems with const member functions as non-type template

  * parameters, somehow it takes them as non-const. mem_fun_explicit workarounds

  * this defficiency by accepting an extra type parameter that specifies the

  * signature of he member function. The workaround was found at:

  *   Daniel, C.:"Re: weird typedef problem in VC",

  *   news:microsoft.public.vc.language, 21st nov 2002, 

  *   http://groups.google.com/groups?

  *     hl=en&lr=&ie=UTF-8&selm=ukwvg3O0BHA.1512%40tkmsftngp05

  */

 template<

   class Class,typename Type,

   typename PtrToMemberFunctionType,PtrToMemberFunctionType PtrToMemberFunction>

 struct const_mem_fun_explicit

 {

   typedef typename remove_reference<Type>::type result_type;

   template<typename ChainedPtr>

 #if !defined(BOOST_NO_SFINAE)

   typename disable_if<

     is_convertible<const ChainedPtr&,const Class&>,Type>::type

 #else

   Type

 #endif

   operator()(const ChainedPtr& x)const

   {

     return operator()(*x);

   }

   Type operator()(const Class& x)const

   {

     return (x.*PtrToMemberFunction)();

   }

   Type operator()(const reference_wrapper<const Class>& x)const

   { 

     return operator()(x.get());

   }

   Type operator()(const reference_wrapper<Class>& x,int=0)const

   { 

     return operator()(x.get());

   }

 };

 template<

   class Class,typename Type,

   typename PtrToMemberFunctionType,PtrToMemberFunctionType PtrToMemberFunction>

 struct mem_fun_explicit

 {

   typedef typename remove_reference<Type>::type result_type;

   template<typename ChainedPtr>

 #if !defined(BOOST_NO_SFINAE)

   typename disable_if<

     is_convertible<ChainedPtr&,Class&>,Type>::type

 #else

   Type

 #endif

   operator()(const ChainedPtr& x)const

   {

     return operator()(*x);

   }

   Type operator()(Class& x)const

   {

     return (x.*PtrToMemberFunction)();

   }

   Type operator()(const reference_wrapper<Class>& x)const

   { 

     return operator()(x.get());

   }

 };

 /* BOOST_MULTI_INDEX_CONST_MEM_FUN and BOOST_MULTI_INDEX_MEM_FUN resolve to

  * mem_fun_explicit for MSVC++ 6.0 and to [const_]mem_fun otherwise.

  */

 #if defined(BOOST_MSVC)&&(BOOST_MSVC<1300)

 #define BOOST_MULTI_INDEX_CONST_MEM_FUN(Class,Type,MemberFunName) \

 ::boost::multi_index::const_mem_fun_explicit<\

   Class,Type,Type (Class::*)()const,&Class::MemberFunName >

 #define BOOST_MULTI_INDEX_MEM_FUN(Class,Type,MemberFunName) \

 ::boost::multi_index::mem_fun_explicit<\

   Class,Type,Type (Class::*)(),&Class::MemberFunName >

 #else

 #define BOOST_MULTI_INDEX_CONST_MEM_FUN(Class,Type,MemberFunName) \

 ::boost::multi_index::const_mem_fun< Class,Type,&Class::MemberFunName >

 #define BOOST_MULTI_INDEX_MEM_FUN(Class,Type,MemberFunName) \

 ::boost::multi_index::mem_fun< Class,Type,&Class::MemberFunName >

 #endif

 } /* namespace multi_index */

 } /* namespace boost */

 #endif