pattern.hh

// This file is a part of Aurelia.
// Copyright (C) 2010  Valentin David
// Copyright (C) 2010  University of Bergen
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
#ifndef __PATTERN_HH
# define __PATTERN_HH

# include <cassert>
# include "../strategies/failure.hh"
# include "../type_traits/has_model.hh"

namespace aurelia {

  template <typename Model>
  struct pattern_concept {
    typedef typename Model::type type;
    typedef typename Model::build_type build_type;
    typedef decltype((std::declval<type&>() =
                      std::declval<build_type>()))
      match_type;

    typedef decltype(*(std::declval<type&>()))
      builder_type;

#ifdef DOC_GEN
    match_type operator=(type&, build_type) throw (failure);
    builder_type operator*(type) throw (failure);
#else
    static_assert(std::is_convertible<builder_type, build_type>::value,
                  "builder_type is not convertible to build_type.");

    static_assert(std::is_convertible<match_type, build_type>::value,
                  "builder_type is not convertible to build_type.");
#endif

    void match(type pattern) {
      try {
        pattern = *pattern;
      }
      catch (failure) {
        assert(false);
      }
    }

    typedef void check;
  };

  template <typename T>
  struct pattern_model {
    typedef void no_model;
  };

  template <typename Pool, typename T>
  struct is_pattern_traits:
    public type_traits::has_model<pattern_model<T> > {
  };

}

#endif