metaparse/v1/transform_error.hpp

0001 #ifndef BOOST_METAPARSE_V1_TRANSFORM_ERROR_HPP
0002 #define BOOST_METAPARSE_V1_TRANSFORM_ERROR_HPP
0003
0004 //    Copyright Abel Sinkovics (abel@sinkovics.hu) 2015.
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
0011 #include <boost/mpl/eval_if.hpp>
0012
0013 namespace boost
0014 {
0015   namespace metaparse
0016   {
0017     namespace v1
0018     {
0019       template <class P, class F>
0020       struct transform_error
0021       {
0022         template <class S, class Pos>
0023         struct apply :
0024           boost::mpl::eval_if<
0025             typename is_error<typename P::template apply<S, Pos> >::type,
0026             typename F::template apply<
0027               typename P::template apply<S, Pos>::type
0028             >,
0029             typename P::template apply<S, Pos>
0030           >
0031         {};
0032
0033         typedef transform_error type;
0034       };
0035     }
0036   }
0037 }
0038
0039 #endif
0040