ceph/src/boost/boost/spirit/home/x3/support/traits/is_parser.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3     Copyright (c) 2014 Agustin Berge
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #if !defined(BOOST_SPIRIT_X3_IS_PARSER_MAY_20_2013_0235PM)
   9 #define BOOST_SPIRIT_X3_IS_PARSER_MAY_20_2013_0235PM
  10
  11 #include <boost/mpl/bool.hpp>
  12 #include <boost/spirit/home/x3/core/parser.hpp>
  13 #include <boost/spirit/home/x3/support/utility/sfinae.hpp>
  14
  15 namespace boost { namespace spirit { namespace x3 { namespace traits
  16 {
  17     ///////////////////////////////////////////////////////////////////////////
  18     // is_parser<T>: metafunction that evaluates to mpl::true_ if a type T
  19     // can be used as a parser, mpl::false_ otherwise
  20     ///////////////////////////////////////////////////////////////////////////
  21     template <typename T, typename Enable = void>
  22     struct is_parser
  23       : mpl::false_
  24     {};
  25
  26     template <typename T>
  27     struct is_parser<T, typename disable_if_substitution_failure<
  28         typename extension::as_parser<T>::type>::type>
  29       : mpl::true_
  30     {};
  31 }}}}
  32
  33 #endif