sl@0: /* Copyright 2003-2006 Joaquín M López Muñoz.
sl@0:  * Distributed under the Boost Software License, Version 1.0.
sl@0:  * (See accompanying file LICENSE_1_0.txt or copy at
sl@0:  * http://www.boost.org/LICENSE_1_0.txt)
sl@0:  *
sl@0:  * See http://www.boost.org/libs/multi_index for library home page.
sl@0:  */
sl@0: 
sl@0: #ifndef BOOST_MULTI_INDEX_MEMBER_HPP
sl@0: #define BOOST_MULTI_INDEX_MEMBER_HPP
sl@0: 
sl@0: #if defined(_MSC_VER)&&(_MSC_VER>=1200)
sl@0: #pragma once
sl@0: #endif
sl@0: 
sl@0: #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
sl@0: #include <boost/mpl/if.hpp>
sl@0: #include <boost/type_traits/is_const.hpp>
sl@0: #include <boost/utility/enable_if.hpp>
sl@0: #include <cstddef>
sl@0: 
sl@0: #if !defined(BOOST_NO_SFINAE)
sl@0: #include <boost/type_traits/is_convertible.hpp>
sl@0: #endif
sl@0: 
sl@0: namespace boost{
sl@0: 
sl@0: template<class T> class reference_wrapper; /* fwd decl. */
sl@0: 
sl@0: namespace multi_index{
sl@0: 
sl@0: namespace detail{
sl@0: 
sl@0: /* member is a read/write key extractor for accessing a given
sl@0:  * member of a class.
sl@0:  * Additionally, member is overloaded to support referece_wrappers
sl@0:  * of T and "chained pointers" to T's. By chained pointer to T we mean
sl@0:  * a type P  such that, given a p of Type P
sl@0:  *   *...n...*x is convertible to T&, for some n>=1.
sl@0:  * Examples of chained pointers are raw and smart pointers, iterators and
sl@0:  * arbitrary combinations of these (vg. T** or auto_ptr<T*>.)
sl@0:  */
sl@0: 
sl@0: /* NB. Some overloads of operator() have an extra dummy parameter int=0.
sl@0:  * This disambiguator serves several purposes:
sl@0:  *  - Without it, MSVC++ 6.0 incorrectly regards some overloads as
sl@0:  *    specializations of a previous member function template.
sl@0:  *  - MSVC++ 6.0/7.0 seem to incorrectly treat some different memfuns
sl@0:  *    as if they have the same signature.
sl@0:  *  - If remove_const is broken due to lack of PTS, int=0 avoids the
sl@0:  *    declaration of memfuns with identical signature.
sl@0:  */
sl@0: 
sl@0: template<class Class,typename Type,Type Class::*PtrToMember>
sl@0: struct const_member_base
sl@0: {
sl@0:   typedef Type result_type;
sl@0: 
sl@0:   template<typename ChainedPtr>
sl@0: 
sl@0: #if !defined(BOOST_NO_SFINAE)
sl@0:   typename disable_if<
sl@0:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
sl@0: #else
sl@0:   Type&
sl@0: #endif
sl@0:   
sl@0:   operator()(const ChainedPtr& x)const
sl@0:   {
sl@0:     return operator()(*x);
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const Class& x)const
sl@0:   {
sl@0:     return x.*PtrToMember;
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const reference_wrapper<const Class>& x)const
sl@0:   {
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const reference_wrapper<Class>& x,int=0)const
sl@0:   { 
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class Class,typename Type,Type Class::*PtrToMember>
sl@0: struct non_const_member_base
sl@0: {
sl@0:   typedef Type result_type;
sl@0: 
sl@0:   template<typename ChainedPtr>
sl@0: 
sl@0: #if !defined(BOOST_NO_SFINAE)
sl@0:   typename disable_if<
sl@0:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
sl@0: #else
sl@0:   Type&
sl@0: #endif
sl@0: 
sl@0:   operator()(const ChainedPtr& x)const
sl@0:   {
sl@0:     return operator()(*x);
sl@0:   }
sl@0: 
sl@0:   const Type& operator()(const Class& x,int=0)const
sl@0:   {
sl@0:     return x.*PtrToMember;
sl@0:   }
sl@0: 
sl@0:   Type& operator()(Class& x)const
sl@0:   { 
sl@0:     return x.*PtrToMember;
sl@0:   }
sl@0: 
sl@0:   const Type& operator()(const reference_wrapper<const Class>& x,int=0)const
sl@0:   {
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const reference_wrapper<Class>& x)const
sl@0:   { 
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: };
sl@0: 
sl@0: } /* namespace multi_index::detail */
sl@0: 
sl@0: template<class Class,typename Type,Type Class::*PtrToMember>
sl@0: struct member:
sl@0:   mpl::if_c<
sl@0:     is_const<Type>::value,
sl@0:     detail::const_member_base<Class,Type,PtrToMember>,
sl@0:     detail::non_const_member_base<Class,Type,PtrToMember>
sl@0:   >::type
sl@0: {
sl@0: };
sl@0: 
sl@0: namespace detail{
sl@0: 
sl@0: /* MSVC++ 6.0 does not support properly pointers to members as
sl@0:  * non-type template arguments, as reported in
sl@0:  *   http://support.microsoft.com/default.aspx?scid=kb;EN-US;249045
sl@0:  * A similar problem (though not identical) is shown by MSVC++ 7.0.
sl@0:  * We provide an alternative to member<> accepting offsets instead
sl@0:  * of pointers to members. This happens to work even for non-POD
sl@0:  * types (although the standard forbids use of offsetof on these),
sl@0:  * so it serves as a workaround in this compiler for all practical
sl@0:  * purposes.
sl@0:  * Surprisingly enough, other compilers, like Intel C++ 7.0/7.1 and
sl@0:  * Visual Age 6.0, have similar bugs. This replacement of member<>
sl@0:  * can be used for them too.
sl@0:  */
sl@0: 
sl@0: template<class Class,typename Type,std::size_t OffsetOfMember>
sl@0: struct const_member_offset_base
sl@0: {
sl@0:   typedef Type result_type;
sl@0: 
sl@0:   template<typename ChainedPtr>
sl@0: 
sl@0: #if !defined(BOOST_NO_SFINAE)
sl@0:   typename disable_if<
sl@0:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
sl@0: #else
sl@0:   Type&
sl@0: #endif 
sl@0:     
sl@0:   operator()(const ChainedPtr& x)const
sl@0:   {
sl@0:     return operator()(*x);
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const Class& x)const
sl@0:   {
sl@0:     return *static_cast<const Type*>(
sl@0:       static_cast<const void*>(
sl@0:         static_cast<const char*>(
sl@0:           static_cast<const void *>(&x))+OffsetOfMember));
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const reference_wrapper<const Class>& x)const
sl@0:   {
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const reference_wrapper<Class>& x,int=0)const
sl@0:   {
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class Class,typename Type,std::size_t OffsetOfMember>
sl@0: struct non_const_member_offset_base
sl@0: {
sl@0:   typedef Type result_type;
sl@0: 
sl@0:   template<typename ChainedPtr>
sl@0: 
sl@0: #if !defined(BOOST_NO_SFINAE)
sl@0:   typename disable_if<
sl@0:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
sl@0: #else
sl@0:   Type&
sl@0: #endif 
sl@0:   
sl@0:   operator()(const ChainedPtr& x)const
sl@0:   {
sl@0:     return operator()(*x);
sl@0:   }
sl@0: 
sl@0:   const Type& operator()(const Class& x,int=0)const
sl@0:   {
sl@0:     return *static_cast<const Type*>(
sl@0:       static_cast<const void*>(
sl@0:         static_cast<const char*>(
sl@0:           static_cast<const void *>(&x))+OffsetOfMember));
sl@0:   }
sl@0: 
sl@0:   Type& operator()(Class& x)const
sl@0:   { 
sl@0:     return *static_cast<Type*>(
sl@0:       static_cast<void*>(
sl@0:         static_cast<char*>(static_cast<void *>(&x))+OffsetOfMember));
sl@0:   }
sl@0: 
sl@0:   const Type& operator()(const reference_wrapper<const Class>& x,int=0)const
sl@0:   {
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: 
sl@0:   Type& operator()(const reference_wrapper<Class>& x)const
sl@0:   {
sl@0:     return operator()(x.get());
sl@0:   }
sl@0: };
sl@0: 
sl@0: } /* namespace multi_index::detail */
sl@0: 
sl@0: template<class Class,typename Type,std::size_t OffsetOfMember>
sl@0: struct member_offset:
sl@0:   mpl::if_c<
sl@0:     is_const<Type>::value,
sl@0:     detail::const_member_offset_base<Class,Type,OffsetOfMember>,
sl@0:     detail::non_const_member_offset_base<Class,Type,OffsetOfMember>
sl@0:   >::type
sl@0: {
sl@0: };
sl@0: 
sl@0: /* BOOST_MULTI_INDEX_MEMBER resolves to member in the normal cases,
sl@0:  * and to member_offset as a workaround in those defective compilers for
sl@0:  * which BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS is defined.
sl@0:  */
sl@0: 
sl@0: #if defined(BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS)
sl@0: #define BOOST_MULTI_INDEX_MEMBER(Class,Type,MemberName) \
sl@0: ::boost::multi_index::member_offset< Class,Type,offsetof(Class,MemberName) >
sl@0: #else
sl@0: #define BOOST_MULTI_INDEX_MEMBER(Class,Type,MemberName) \
sl@0: ::boost::multi_index::member< Class,Type,&Class::MemberName >
sl@0: #endif
sl@0: 
sl@0: } /* namespace multi_index */
sl@0: 
sl@0: } /* namespace boost */
sl@0: 
sl@0: #endif