fusion/support/as_const.hpp

0001 /*=============================================================================
0002     Copyright (c) 2012 Nathan Ridge
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007 #ifndef BOOST_FUSION_SUPPORT_AS_CONST_HPP
0008 #define BOOST_FUSION_SUPPORT_AS_CONST_HPP
0009
0010 #include <boost/config.hpp>
0011 #include <boost/fusion/support/config.hpp>
0012
0013 namespace boost { namespace fusion { namespace extension
0014 {
0015     // A customization point that allows certain wrappers around
0016     // Fusion sequence elements (e.g. adt_attribute_proxy) to be
0017     // unwrapped in contexts where the element only needs to be
0018     // read. The library wraps accesses to Fusion elements in
0019     // such contexts with calls to this function. Users can
0020     // specialize this function for their own wrappers.
0021     template <typename T>
0022     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0023     inline const T& as_const(const T& obj) BOOST_NOEXCEPT
0024     {
0025         return obj;
0026     }
0027
0028 }}}
0029
0030 #endif