Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2007 Tobias Schwinger
Chris@16:   
Chris@16:     Use modification and distribution are subject to the Boost Software 
Chris@16:     License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:     http://www.boost.org/LICENSE_1_0.txt).
Chris@16: ==============================================================================*/
Chris@16: 
Chris@16: #if !defined(BOOST_FUSION_SUPPORT_DEDUCE_HPP_INCLUDED)
Chris@16: #define BOOST_FUSION_SUPPORT_DEDUCE_HPP_INCLUDED
Chris@16: 
Chris@101: #include <boost/fusion/support/config.hpp>
Chris@16: #include <boost/ref.hpp>
Chris@16: 
Chris@101: #ifndef BOOST_NO_CXX11_HDR_FUNCTIONAL
Chris@101: #include <functional>
Chris@101: #endif
Chris@101: 
Chris@16: namespace boost { namespace fusion { namespace traits
Chris@16: {
Chris@16:     template <typename T> struct deduce;
Chris@16: 
Chris@16:     //----- ---- --- -- - -  -   -
Chris@16: 
Chris@16:     // Non-references pass unchanged
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce
Chris@16:     {
Chris@16:         typedef T type; 
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T const>
Chris@16:     {
Chris@16:         typedef T type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T volatile>
Chris@16:     {
Chris@16:         typedef T type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T const volatile>
Chris@16:     {
Chris@16:         typedef T type;
Chris@16:     };
Chris@16: 
Chris@16:     // Keep references on mutable LValues
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T &>
Chris@16:     {
Chris@16:         typedef T & type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T volatile&>
Chris@16:     {
Chris@16:         typedef T volatile& type;
Chris@16:     };
Chris@16: 
Chris@16:     // Store away potential RValues
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T const&>
Chris@16:     {
Chris@16:         typedef T type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<T const volatile&>
Chris@16:     {
Chris@16:         typedef T type;
Chris@16:     };
Chris@16: 
Chris@16:     // Unwrap Boost.RefS (referencee cv is deduced)
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<reference_wrapper<T> & >
Chris@16:     {
Chris@16:         typedef T& type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     struct deduce<reference_wrapper<T> const & >
Chris@16:     {
Chris@16:         typedef T& type;
Chris@16:     };
Chris@16: 
Chris@101:     // Also unwrap C++11 std::ref if available (referencee cv is deduced)
Chris@101: #ifndef BOOST_NO_CXX11_HDR_FUNCTIONAL
Chris@101:     template <typename T>
Chris@101:     struct deduce<std::reference_wrapper<T> &>
Chris@101:     {
Chris@101:         typedef T& type;
Chris@101:     };
Chris@101: 
Chris@101:     template <typename T>
Chris@101:     struct deduce<std::reference_wrapper<T> const &>
Chris@101:     {
Chris@101:         typedef T& type;
Chris@101:     };
Chris@101: #endif
Chris@101: 
Chris@16:     // Keep references on arrays, even if const
Chris@16: 
Chris@16:     template <typename T, int N>
Chris@16:     struct deduce<T(&)[N]>
Chris@16:     {
Chris@16:         typedef T(&type)[N];
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T, int N>
Chris@16:     struct deduce<volatile T(&)[N]>
Chris@16:     {
Chris@16:         typedef volatile T(&type)[N]; 
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T, int N>
Chris@16:     struct deduce<const T(&)[N]>
Chris@16:     {
Chris@16:         typedef const T(&type)[N];
Chris@16:     };
Chris@16: 
Chris@16:     template <typename T, int N>
Chris@16:     struct deduce<const volatile T(&)[N]>
Chris@16:     {
Chris@16:         typedef const volatile T(&type)[N];
Chris@16:     };
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: #endif
Chris@16: