| /* 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_GLOBAL_FUN_HPP |
| #define BOOST_MULTI_INDEX_GLOBAL_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/is_const.hpp> |
| #include <boost/type_traits/is_reference.hpp> |
| #include <boost/type_traits/remove_const.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{ |
| |
| namespace detail{ |
| |
| /* global_fun is a read-only key extractor from Value based on a given global |
| * (or static member) function with signature: |
| * |
| * Type f([const] Value [&]); |
| * |
| * Additionally, global_fun and const_global_fun are overloaded to support |
| * referece_wrappers of Value and "chained pointers" to Value'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 Value,typename Type,Type (*PtrToFunction)(Value)> |
| struct const_ref_global_fun_base |
| { |
| typedef typename remove_reference<Type>::type result_type; |
| |
| template<typename ChainedPtr> |
| |
| #if !defined(BOOST_NO_SFINAE) |
| typename disable_if< |
| is_convertible<const ChainedPtr&,Value>,Type>::type |
| #else |
| Type |
| #endif |
| |
| operator()(const ChainedPtr& x)const |
| { |
| return operator()(*x); |
| } |
| |
| Type operator()(Value x)const |
| { |
| return PtrToFunction(x); |
| } |
| |
| Type operator()( |
| const reference_wrapper< |
| typename remove_reference<Value>::type>& x)const |
| { |
| return operator()(x.get()); |
| } |
| |
| Type operator()( |
| const reference_wrapper< |
| typename remove_const< |
| typename remove_reference<Value>::type>::type>& x,int=0)const |
| { |
| return operator()(x.get()); |
| } |
| }; |
| |
| template<class Value,typename Type,Type (*PtrToFunction)(Value)> |
| struct non_const_ref_global_fun_base |
| { |
| typedef typename remove_reference<Type>::type result_type; |
| |
| template<typename ChainedPtr> |
| |
| #if !defined(BOOST_NO_SFINAE) |
| typename disable_if< |
| is_convertible<ChainedPtr&,Value>,Type>::type |
| #else |
| Type |
| #endif |
| |
| operator()(const ChainedPtr& x)const |
| { |
| return operator()(*x); |
| } |
| |
| Type operator()(Value x)const |
| { |
| return PtrToFunction(x); |
| } |
| |
| Type operator()( |
| const reference_wrapper< |
| typename remove_reference<Value>::type>& x)const |
| { |
| return operator()(x.get()); |
| } |
| }; |
| |
| template<class Value,typename Type,Type (*PtrToFunction)(Value)> |
| struct non_ref_global_fun_base |
| { |
| typedef typename remove_reference<Type>::type result_type; |
| |
| template<typename ChainedPtr> |
| |
| #if !defined(BOOST_NO_SFINAE) |
| typename disable_if< |
| is_convertible<const ChainedPtr&,const Value&>,Type>::type |
| #else |
| Type |
| #endif |
| |
| operator()(const ChainedPtr& x)const |
| { |
| return operator()(*x); |
| } |
| |
| Type operator()(const Value& x)const |
| { |
| return PtrToFunction(x); |
| } |
| |
| Type operator()(const reference_wrapper<const Value>& x)const |
| { |
| return operator()(x.get()); |
| } |
| |
| Type operator()( |
| const reference_wrapper< |
| typename remove_const<Value>::type>& x,int=0)const |
| { |
| return operator()(x.get()); |
| } |
| }; |
| |
| } /* namespace multi_index::detail */ |
| |
| template<class Value,typename Type,Type (*PtrToFunction)(Value)> |
| struct global_fun: |
| mpl::if_c< |
| is_reference<Value>::value, |
| typename mpl::if_c< |
| is_const<typename remove_reference<Value>::type>::value, |
| detail::const_ref_global_fun_base<Value,Type,PtrToFunction>, |
| detail::non_const_ref_global_fun_base<Value,Type,PtrToFunction> |
| >::type, |
| detail::non_ref_global_fun_base<Value,Type,PtrToFunction> |
| >::type |
| { |
| }; |
| |
| } /* namespace multi_index */ |
| |
| } /* namespace boost */ |
| |
| #endif |