metaparse/v1/change_error_message.hpp

0001 #ifndef BOOST_METAPARSE_V1_CHANGE_ERROR_MESSAGE_HPP
0002 #define BOOST_METAPARSE_V1_CHANGE_ERROR_MESSAGE_HPP
0003
0004 //    Copyright Abel Sinkovics (abel@sinkovics.hu) 2011.
0005 // Distributed under the Boost Software License, Version 1.0.
0006 //    (See accompanying file LICENSE_1_0.txt or copy at
0007 //          http://www.boost.org/LICENSE_1_0.txt)
0008
0009 #include <boost/metaparse/v1/is_error.hpp>
0010 #include <boost/metaparse/v1/reject.hpp>
0011
0012 #include <boost/mpl/eval_if.hpp>
0013
0014 namespace boost
0015 {
0016   namespace metaparse
0017   {
0018     namespace v1
0019     {
0020       template <class P, class Msg>
0021       struct change_error_message
0022       {
0023         template <class S, class Pos>
0024         struct apply :
0025           boost::mpl::eval_if<
0026             typename is_error<typename P::template apply<S, Pos> >::type,
0027             reject<Msg, Pos>,
0028             typename P::template apply<S, Pos>
0029           >
0030         {};
0031
0032         typedef change_error_message type;
0033       };
0034     }
0035   }
0036 }
0037
0038 #endif
0039