williamr@2: /* Copyright 2003-2006 Joaquín M López Muñoz.
williamr@2:  * Distributed under the Boost Software License, Version 1.0.
williamr@2:  * (See accompanying file LICENSE_1_0.txt or copy at
williamr@2:  * http://www.boost.org/LICENSE_1_0.txt)
williamr@2:  *
williamr@2:  * See http://www.boost.org/libs/multi_index for library home page.
williamr@2:  */
williamr@2: 
williamr@2: #ifndef BOOST_MULTI_INDEX_MEM_FUN_HPP
williamr@2: #define BOOST_MULTI_INDEX_MEM_FUN_HPP
williamr@2: 
williamr@2: #if defined(_MSC_VER)&&(_MSC_VER>=1200)
williamr@2: #pragma once
williamr@2: #endif
williamr@2: 
williamr@2: #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
williamr@2: #include <boost/mpl/if.hpp>
williamr@2: #include <boost/type_traits/remove_reference.hpp>
williamr@2: #include <boost/utility/enable_if.hpp>
williamr@2: 
williamr@2: #if !defined(BOOST_NO_SFINAE)
williamr@2: #include <boost/type_traits/is_convertible.hpp>
williamr@2: #endif
williamr@2: 
williamr@2: namespace boost{
williamr@2: 
williamr@2: template<class T> class reference_wrapper; /* fwd decl. */
williamr@2: 
williamr@2: namespace multi_index{
williamr@2: 
williamr@2: /* mem_fun implements a read-only key extractor based on a given non-const
williamr@2:  * member function of a class.
williamr@2:  * const_mem_fun does the same for const member functions.
williamr@2:  * Additionally, mem_fun  and const_mem_fun are overloaded to support
williamr@2:  * referece_wrappers of T and "chained pointers" to T's. By chained pointer
williamr@2:  * to T we  mean a type P such that, given a p of Type P
williamr@2:  *   *...n...*x is convertible to T&, for some n>=1.
williamr@2:  * Examples of chained pointers are raw and smart pointers, iterators and
williamr@2:  * arbitrary combinations of these (vg. T** or auto_ptr<T*>.)
williamr@2:  */
williamr@2: 
williamr@2: /* NB. Some overloads of operator() have an extra dummy parameter int=0.
williamr@2:  * This disambiguator serves several purposes:
williamr@2:  *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as
williamr@2:  *    specializations of a previous member function template.
williamr@2:  *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns
williamr@2:  *    as if they have the same signature.
williamr@2:  *  - If remove_const is broken due to lack of PTS, int=0 avoids the
williamr@2:  *    declaration of memfuns with identical signature.
williamr@2:  */
williamr@2: 
williamr@2: template<class Class,typename Type,Type (Class::*PtrToMemberFunction)()const>
williamr@2: struct const_mem_fun
williamr@2: {
williamr@2:   typedef typename remove_reference<Type>::type result_type;
williamr@2: 
williamr@2:   template<typename ChainedPtr>
williamr@2: 
williamr@2: #if !defined(BOOST_NO_SFINAE)
williamr@2:   typename disable_if<
williamr@2:     is_convertible<const ChainedPtr&,const Class&>,Type>::type
williamr@2: #else
williamr@2:   Type
williamr@2: #endif
williamr@2: 
williamr@2:   operator()(const ChainedPtr& x)const
williamr@2:   {
williamr@2:     return operator()(*x);
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const Class& x)const
williamr@2:   {
williamr@2:     return (x.*PtrToMemberFunction)();
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const reference_wrapper<const Class>& x)const
williamr@2:   { 
williamr@2:     return operator()(x.get());
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const reference_wrapper<Class>& x,int=0)const
williamr@2:   { 
williamr@2:     return operator()(x.get());
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: template<class Class,typename Type,Type (Class::*PtrToMemberFunction)()>
williamr@2: struct mem_fun
williamr@2: {
williamr@2:   typedef typename remove_reference<Type>::type result_type;
williamr@2: 
williamr@2:   template<typename ChainedPtr>
williamr@2: 
williamr@2: #if !defined(BOOST_NO_SFINAE)
williamr@2:   typename disable_if<
williamr@2:     is_convertible<ChainedPtr&,Class&>,Type>::type
williamr@2: #else
williamr@2:   Type
williamr@2: #endif
williamr@2: 
williamr@2:   operator()(const ChainedPtr& x)const
williamr@2:   {
williamr@2:     return operator()(*x);
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(Class& x)const
williamr@2:   {
williamr@2:     return (x.*PtrToMemberFunction)();
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const reference_wrapper<Class>& x)const
williamr@2:   { 
williamr@2:     return operator()(x.get());
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: /* MSVC++ 6.0 has problems with const member functions as non-type template
williamr@2:  * parameters, somehow it takes them as non-const. mem_fun_explicit workarounds
williamr@2:  * this defficiency by accepting an extra type parameter that specifies the
williamr@2:  * signature of he member function. The workaround was found at:
williamr@2:  *   Daniel, C.:"Re: weird typedef problem in VC",
williamr@2:  *   news:microsoft.public.vc.language, 21st nov 2002, 
williamr@2:  *   http://groups.google.com/groups?
williamr@2:  *     hl=en&lr=&ie=UTF-8&selm=ukwvg3O0BHA.1512%40tkmsftngp05
williamr@2:  */
williamr@2: 
williamr@2: template<
williamr@2:   class Class,typename Type,
williamr@2:   typename PtrToMemberFunctionType,PtrToMemberFunctionType PtrToMemberFunction>
williamr@2: struct const_mem_fun_explicit
williamr@2: {
williamr@2:   typedef typename remove_reference<Type>::type result_type;
williamr@2: 
williamr@2:   template<typename ChainedPtr>
williamr@2: 
williamr@2: #if !defined(BOOST_NO_SFINAE)
williamr@2:   typename disable_if<
williamr@2:     is_convertible<const ChainedPtr&,const Class&>,Type>::type
williamr@2: #else
williamr@2:   Type
williamr@2: #endif
williamr@2: 
williamr@2:   operator()(const ChainedPtr& x)const
williamr@2:   {
williamr@2:     return operator()(*x);
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const Class& x)const
williamr@2:   {
williamr@2:     return (x.*PtrToMemberFunction)();
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const reference_wrapper<const Class>& x)const
williamr@2:   { 
williamr@2:     return operator()(x.get());
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const reference_wrapper<Class>& x,int=0)const
williamr@2:   { 
williamr@2:     return operator()(x.get());
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: template<
williamr@2:   class Class,typename Type,
williamr@2:   typename PtrToMemberFunctionType,PtrToMemberFunctionType PtrToMemberFunction>
williamr@2: struct mem_fun_explicit
williamr@2: {
williamr@2:   typedef typename remove_reference<Type>::type result_type;
williamr@2: 
williamr@2:   template<typename ChainedPtr>
williamr@2: 
williamr@2: #if !defined(BOOST_NO_SFINAE)
williamr@2:   typename disable_if<
williamr@2:     is_convertible<ChainedPtr&,Class&>,Type>::type
williamr@2: #else
williamr@2:   Type
williamr@2: #endif
williamr@2: 
williamr@2:   operator()(const ChainedPtr& x)const
williamr@2:   {
williamr@2:     return operator()(*x);
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(Class& x)const
williamr@2:   {
williamr@2:     return (x.*PtrToMemberFunction)();
williamr@2:   }
williamr@2: 
williamr@2:   Type operator()(const reference_wrapper<Class>& x)const
williamr@2:   { 
williamr@2:     return operator()(x.get());
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: /* BOOST_MULTI_INDEX_CONST_MEM_FUN and BOOST_MULTI_INDEX_MEM_FUN resolve to
williamr@2:  * mem_fun_explicit for MSVC++ 6.0 and to [const_]mem_fun otherwise.
williamr@2:  */
williamr@2: 
williamr@2: #if defined(BOOST_MSVC)&&(BOOST_MSVC<1300)
williamr@2: 
williamr@2: #define BOOST_MULTI_INDEX_CONST_MEM_FUN(Class,Type,MemberFunName) \
williamr@2: ::boost::multi_index::const_mem_fun_explicit<\
williamr@2:   Class,Type,Type (Class::*)()const,&Class::MemberFunName >
williamr@2: #define BOOST_MULTI_INDEX_MEM_FUN(Class,Type,MemberFunName) \
williamr@2: ::boost::multi_index::mem_fun_explicit<\
williamr@2:   Class,Type,Type (Class::*)(),&Class::MemberFunName >
williamr@2: 
williamr@2: #else
williamr@2: 
williamr@2: #define BOOST_MULTI_INDEX_CONST_MEM_FUN(Class,Type,MemberFunName) \
williamr@2: ::boost::multi_index::const_mem_fun< Class,Type,&Class::MemberFunName >
williamr@2: #define BOOST_MULTI_INDEX_MEM_FUN(Class,Type,MemberFunName) \
williamr@2: ::boost::multi_index::mem_fun< Class,Type,&Class::MemberFunName >
williamr@2: 
williamr@2: #endif
williamr@2: 
williamr@2: } /* namespace multi_index */
williamr@2: 
williamr@2: } /* namespace boost */
williamr@2: 
williamr@2: #endif