| /*============================================================================= |
| Copyright (c) 2007 Tobias Schwinger |
| |
| Use modification and distribution are subject to 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). |
| ==============================================================================*/ |
| |
| #if !defined(BOOST_FUSION_SUPPORT_DEDUCE_HPP_INCLUDED) |
| #define BOOST_FUSION_SUPPORT_DEDUCE_HPP_INCLUDED |
| |
| #include <boost/ref.hpp> |
| |
| namespace boost { namespace fusion { namespace traits |
| { |
| template <typename T> struct deduce; |
| |
| //----- ---- --- -- - - - - |
| |
| // Non-references pass unchanged |
| |
| template <typename T> |
| struct deduce |
| { |
| typedef T type; |
| }; |
| |
| template <typename T> |
| struct deduce<T const> |
| { |
| typedef T type; |
| }; |
| |
| template <typename T> |
| struct deduce<T volatile> |
| { |
| typedef T type; |
| }; |
| |
| template <typename T> |
| struct deduce<T const volatile> |
| { |
| typedef T type; |
| }; |
| |
| // Keep references on mutable LValues |
| |
| template <typename T> |
| struct deduce<T &> |
| { |
| typedef T & type; |
| }; |
| |
| template <typename T> |
| struct deduce<T volatile&> |
| { |
| typedef T volatile& type; |
| }; |
| |
| // Store away potential RValues |
| |
| template <typename T> |
| struct deduce<T const&> |
| { |
| typedef T type; |
| }; |
| |
| template <typename T> |
| struct deduce<T const volatile&> |
| { |
| typedef T type; |
| }; |
| |
| // Unwrap Boost.RefS (referencee cv is deduced) |
| |
| template <typename T> |
| struct deduce<reference_wrapper<T> & > |
| { |
| typedef T& type; |
| }; |
| |
| template <typename T> |
| struct deduce<reference_wrapper<T> const & > |
| { |
| typedef T& type; |
| }; |
| |
| // Keep references on arrays, even if const |
| |
| template <typename T, int N> |
| struct deduce<T(&)[N]> |
| { |
| typedef T(&type)[N]; |
| }; |
| |
| template <typename T, int N> |
| struct deduce<volatile T(&)[N]> |
| { |
| typedef volatile T(&type)[N]; |
| }; |
| |
| template <typename T, int N> |
| struct deduce<const T(&)[N]> |
| { |
| typedef const T(&type)[N]; |
| }; |
| |
| template <typename T, int N> |
| struct deduce<const volatile T(&)[N]> |
| { |
| typedef const volatile T(&type)[N]; |
| }; |
| |
| }}} |
| |
| #endif |
| |