support/traits/is_parser.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2014 Joel de Guzman
0003     Copyright (c) 2014 Agustin Berge
0004
0005     Distributed under the Boost Software License, Version 1.0. (See accompanying
0006     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 ==============================================================================*/
0008 #if !defined(BOOST_SPIRIT_X3_IS_PARSER_MAY_20_2013_0235PM)
0009 #define BOOST_SPIRIT_X3_IS_PARSER_MAY_20_2013_0235PM
0010
0011 #include <boost/mpl/bool.hpp>
0012 #include <boost/spirit/home/x3/core/parser.hpp>
0013 #include <boost/spirit/home/x3/support/utility/sfinae.hpp>
0014
0015 namespace boost { namespace spirit { namespace x3 { namespace traits
0016 {
0017     ///////////////////////////////////////////////////////////////////////////
0018     // is_parser<T>: metafunction that evaluates to mpl::true_ if a type T
0019     // can be used as a parser, mpl::false_ otherwise
0020     ///////////////////////////////////////////////////////////////////////////
0021     template <typename T, typename Enable = void>
0022     struct is_parser
0023       : mpl::false_
0024     {};
0025
0026     template <typename T>
0027     struct is_parser<T, typename disable_if_substitution_failure<
0028         typename extension::as_parser<T>::type>::type>
0029       : mpl::true_
0030     {};
0031 }}}}
0032
0033 #endif