Chris@101: /* Copyright 2003-2013 Joaquin M Lopez Munoz.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  * (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  * http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  *
Chris@16:  * See http://www.boost.org/libs/multi_index for library home page.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_MULTI_INDEX_MEMBER_HPP
Chris@16: #define BOOST_MULTI_INDEX_MEMBER_HPP
Chris@16: 
Chris@101: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/type_traits/is_const.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: #include <cstddef>
Chris@16: 
Chris@16: #if !defined(BOOST_NO_SFINAE)
Chris@16: #include <boost/type_traits/is_convertible.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost{
Chris@16: 
Chris@16: template<class T> class reference_wrapper; /* fwd decl. */
Chris@16: 
Chris@16: namespace multi_index{
Chris@16: 
Chris@16: namespace detail{
Chris@16: 
Chris@16: /* member is a read/write key extractor for accessing a given
Chris@16:  * member of a class.
Chris@16:  * Additionally, member is overloaded to support referece_wrappers
Chris@16:  * of T and "chained pointers" to T's. By chained pointer to T we mean
Chris@16:  * a type P  such that, given a p of Type P
Chris@16:  *   *...n...*x is convertible to T&, for some n>=1.
Chris@16:  * Examples of chained pointers are raw and smart pointers, iterators and
Chris@16:  * arbitrary combinations of these (vg. T** or auto_ptr<T*>.)
Chris@16:  */
Chris@16: 
Chris@16: template<class Class,typename Type,Type Class::*PtrToMember>
Chris@16: struct const_member_base
Chris@16: {
Chris@16:   typedef Type result_type;
Chris@16: 
Chris@16:   template<typename ChainedPtr>
Chris@16: 
Chris@16: #if !defined(BOOST_NO_SFINAE)
Chris@16:   typename disable_if<
Chris@16:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
Chris@16: #else
Chris@16:   Type&
Chris@16: #endif
Chris@16:   
Chris@16:   operator()(const ChainedPtr& x)const
Chris@16:   {
Chris@16:     return operator()(*x);
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(const Class& x)const
Chris@16:   {
Chris@16:     return x.*PtrToMember;
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(const reference_wrapper<const Class>& x)const
Chris@16:   {
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: 
Chris@101:   Type& operator()(const reference_wrapper<Class>& x)const
Chris@16:   { 
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template<class Class,typename Type,Type Class::*PtrToMember>
Chris@16: struct non_const_member_base
Chris@16: {
Chris@16:   typedef Type result_type;
Chris@16: 
Chris@16:   template<typename ChainedPtr>
Chris@16: 
Chris@16: #if !defined(BOOST_NO_SFINAE)
Chris@16:   typename disable_if<
Chris@16:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
Chris@16: #else
Chris@16:   Type&
Chris@16: #endif
Chris@16: 
Chris@16:   operator()(const ChainedPtr& x)const
Chris@16:   {
Chris@16:     return operator()(*x);
Chris@16:   }
Chris@16: 
Chris@101:   const Type& operator()(const Class& x)const
Chris@16:   {
Chris@16:     return x.*PtrToMember;
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(Class& x)const
Chris@16:   { 
Chris@16:     return x.*PtrToMember;
Chris@16:   }
Chris@16: 
Chris@101:   const Type& operator()(const reference_wrapper<const Class>& x)const
Chris@16:   {
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(const reference_wrapper<Class>& x)const
Chris@16:   { 
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: } /* namespace multi_index::detail */
Chris@16: 
Chris@16: template<class Class,typename Type,Type Class::*PtrToMember>
Chris@16: struct member:
Chris@16:   mpl::if_c<
Chris@16:     is_const<Type>::value,
Chris@16:     detail::const_member_base<Class,Type,PtrToMember>,
Chris@16:     detail::non_const_member_base<Class,Type,PtrToMember>
Chris@16:   >::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: namespace detail{
Chris@16: 
Chris@16: /* MSVC++ 6.0 does not support properly pointers to members as
Chris@16:  * non-type template arguments, as reported in
Chris@16:  *   http://support.microsoft.com/default.aspx?scid=kb;EN-US;249045
Chris@16:  * A similar problem (though not identical) is shown by MSVC++ 7.0.
Chris@16:  * We provide an alternative to member<> accepting offsets instead
Chris@16:  * of pointers to members. This happens to work even for non-POD
Chris@16:  * types (although the standard forbids use of offsetof on these),
Chris@16:  * so it serves as a workaround in this compiler for all practical
Chris@16:  * purposes.
Chris@16:  * Surprisingly enough, other compilers, like Intel C++ 7.0/7.1 and
Chris@16:  * Visual Age 6.0, have similar bugs. This replacement of member<>
Chris@16:  * can be used for them too.
Chris@101:  *
Chris@101:  * Support for such old compilers is dropped and
Chris@101:  * [non_]const_member_offset_base is deprecated.
Chris@16:  */
Chris@16: 
Chris@16: template<class Class,typename Type,std::size_t OffsetOfMember>
Chris@16: struct const_member_offset_base
Chris@16: {
Chris@16:   typedef Type result_type;
Chris@16: 
Chris@16:   template<typename ChainedPtr>
Chris@16: 
Chris@16: #if !defined(BOOST_NO_SFINAE)
Chris@16:   typename disable_if<
Chris@16:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
Chris@16: #else
Chris@16:   Type&
Chris@16: #endif 
Chris@16:     
Chris@16:   operator()(const ChainedPtr& x)const
Chris@16:   {
Chris@16:     return operator()(*x);
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(const Class& x)const
Chris@16:   {
Chris@16:     return *static_cast<const Type*>(
Chris@16:       static_cast<const void*>(
Chris@16:         static_cast<const char*>(
Chris@16:           static_cast<const void *>(&x))+OffsetOfMember));
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(const reference_wrapper<const Class>& x)const
Chris@16:   {
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: 
Chris@101:   Type& operator()(const reference_wrapper<Class>& x)const
Chris@16:   {
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template<class Class,typename Type,std::size_t OffsetOfMember>
Chris@16: struct non_const_member_offset_base
Chris@16: {
Chris@16:   typedef Type result_type;
Chris@16: 
Chris@16:   template<typename ChainedPtr>
Chris@16: 
Chris@16: #if !defined(BOOST_NO_SFINAE)
Chris@16:   typename disable_if<
Chris@16:     is_convertible<const ChainedPtr&,const Class&>,Type&>::type
Chris@16: #else
Chris@16:   Type&
Chris@16: #endif 
Chris@16:   
Chris@16:   operator()(const ChainedPtr& x)const
Chris@16:   {
Chris@16:     return operator()(*x);
Chris@16:   }
Chris@16: 
Chris@101:   const Type& operator()(const Class& x)const
Chris@16:   {
Chris@16:     return *static_cast<const Type*>(
Chris@16:       static_cast<const void*>(
Chris@16:         static_cast<const char*>(
Chris@16:           static_cast<const void *>(&x))+OffsetOfMember));
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(Class& x)const
Chris@16:   { 
Chris@16:     return *static_cast<Type*>(
Chris@16:       static_cast<void*>(
Chris@16:         static_cast<char*>(static_cast<void *>(&x))+OffsetOfMember));
Chris@16:   }
Chris@16: 
Chris@101:   const Type& operator()(const reference_wrapper<const Class>& x)const
Chris@16:   {
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: 
Chris@16:   Type& operator()(const reference_wrapper<Class>& x)const
Chris@16:   {
Chris@16:     return operator()(x.get());
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: } /* namespace multi_index::detail */
Chris@16: 
Chris@16: template<class Class,typename Type,std::size_t OffsetOfMember>
Chris@16: struct member_offset:
Chris@16:   mpl::if_c<
Chris@16:     is_const<Type>::value,
Chris@16:     detail::const_member_offset_base<Class,Type,OffsetOfMember>,
Chris@16:     detail::non_const_member_offset_base<Class,Type,OffsetOfMember>
Chris@16:   >::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: /* BOOST_MULTI_INDEX_MEMBER resolves to member in the normal cases,
Chris@16:  * and to member_offset as a workaround in those defective compilers for
Chris@16:  * which BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS is defined.
Chris@16:  */
Chris@16: 
Chris@16: #if defined(BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS)
Chris@16: #define BOOST_MULTI_INDEX_MEMBER(Class,Type,MemberName) \
Chris@16: ::boost::multi_index::member_offset< Class,Type,offsetof(Class,MemberName) >
Chris@16: #else
Chris@16: #define BOOST_MULTI_INDEX_MEMBER(Class,Type,MemberName) \
Chris@16: ::boost::multi_index::member< Class,Type,&Class::MemberName >
Chris@16: #endif
Chris@16: 
Chris@16: } /* namespace multi_index */
Chris@16: 
Chris@16: } /* namespace boost */
Chris@16: 
Chris@16: #endif