/* Copyright 2003-2008 Joaquin M Lopez Munoz. | |
* 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_MEMBER_HPP | |
#define BOOST_MULTI_INDEX_MEMBER_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/is_const.hpp> | |
#include <boost/utility/enable_if.hpp> | |
#include <cstddef> | |
#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{ | |
namespace detail{ | |
/* member is a read/write key extractor for accessing a given | |
* member of a class. | |
* Additionally, member is 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::*PtrToMember> | |
struct const_member_base | |
{ | |
typedef 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.*PtrToMember; | |
} | |
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::*PtrToMember> | |
struct non_const_member_base | |
{ | |
typedef 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); | |
} | |
const Type& operator()(const Class& x,int=0)const | |
{ | |
return x.*PtrToMember; | |
} | |
Type& operator()(Class& x)const | |
{ | |
return x.*PtrToMember; | |
} | |
const Type& operator()(const reference_wrapper<const Class>& x,int=0)const | |
{ | |
return operator()(x.get()); | |
} | |
Type& operator()(const reference_wrapper<Class>& x)const | |
{ | |
return operator()(x.get()); | |
} | |
}; | |
} /* namespace multi_index::detail */ | |
template<class Class,typename Type,Type Class::*PtrToMember> | |
struct member: | |
mpl::if_c< | |
is_const<Type>::value, | |
detail::const_member_base<Class,Type,PtrToMember>, | |
detail::non_const_member_base<Class,Type,PtrToMember> | |
>::type | |
{ | |
}; | |
namespace detail{ | |
/* MSVC++ 6.0 does not support properly pointers to members as | |
* non-type template arguments, as reported in | |
* http://support.microsoft.com/default.aspx?scid=kb;EN-US;249045 | |
* A similar problem (though not identical) is shown by MSVC++ 7.0. | |
* We provide an alternative to member<> accepting offsets instead | |
* of pointers to members. This happens to work even for non-POD | |
* types (although the standard forbids use of offsetof on these), | |
* so it serves as a workaround in this compiler for all practical | |
* purposes. | |
* Surprisingly enough, other compilers, like Intel C++ 7.0/7.1 and | |
* Visual Age 6.0, have similar bugs. This replacement of member<> | |
* can be used for them too. | |
*/ | |
template<class Class,typename Type,std::size_t OffsetOfMember> | |
struct const_member_offset_base | |
{ | |
typedef 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 *static_cast<const Type*>( | |
static_cast<const void*>( | |
static_cast<const char*>( | |
static_cast<const void *>(&x))+OffsetOfMember)); | |
} | |
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,std::size_t OffsetOfMember> | |
struct non_const_member_offset_base | |
{ | |
typedef 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); | |
} | |
const Type& operator()(const Class& x,int=0)const | |
{ | |
return *static_cast<const Type*>( | |
static_cast<const void*>( | |
static_cast<const char*>( | |
static_cast<const void *>(&x))+OffsetOfMember)); | |
} | |
Type& operator()(Class& x)const | |
{ | |
return *static_cast<Type*>( | |
static_cast<void*>( | |
static_cast<char*>(static_cast<void *>(&x))+OffsetOfMember)); | |
} | |
const Type& operator()(const reference_wrapper<const Class>& x,int=0)const | |
{ | |
return operator()(x.get()); | |
} | |
Type& operator()(const reference_wrapper<Class>& x)const | |
{ | |
return operator()(x.get()); | |
} | |
}; | |
} /* namespace multi_index::detail */ | |
template<class Class,typename Type,std::size_t OffsetOfMember> | |
struct member_offset: | |
mpl::if_c< | |
is_const<Type>::value, | |
detail::const_member_offset_base<Class,Type,OffsetOfMember>, | |
detail::non_const_member_offset_base<Class,Type,OffsetOfMember> | |
>::type | |
{ | |
}; | |
/* BOOST_MULTI_INDEX_MEMBER resolves to member in the normal cases, | |
* and to member_offset as a workaround in those defective compilers for | |
* which BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS is defined. | |
*/ | |
#if defined(BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS) | |
#define BOOST_MULTI_INDEX_MEMBER(Class,Type,MemberName) \ | |
::boost::multi_index::member_offset< Class,Type,offsetof(Class,MemberName) > | |
#else | |
#define BOOST_MULTI_INDEX_MEMBER(Class,Type,MemberName) \ | |
::boost::multi_index::member< Class,Type,&Class::MemberName > | |
#endif | |
} /* namespace multi_index */ | |
} /* namespace boost */ | |
#endif |