from_value_to_value.hh

// Copyright (C) 2008, 2009 EPITA Research and Development Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena 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, version 2 of the License.
//
// Olena 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 Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to produce
// an executable, this file does not by itself cause the resulting
// executable to be covered by the GNU General Public License.  This
// exception does not however invalidate any other reasons why the
// executable file might be covered by the GNU General Public License.

#ifndef MLN_CONVERT_IMPL_FROM_VALUE_TO_VALUE_HH
# define MLN_CONVERT_IMPL_FROM_VALUE_TO_VALUE_HH



# include <utility>
# include <mln/core/concept/image.hh>
# include <mln/core/concept/site_set.hh>
# include <mln/value/concept/all.hh>

# include <mln/core/site_set/p_run.hh>
# include <mln/metal/converts_to.hh>

# include <mln/convert/from_to.hxx>

namespace mln
{

  namespace convert
  {

    namespace impl
    {

      template <typename V, typename W>
      void
      from_value_to_value(const Value<V>& from, Value<W>& to);

      template <typename V>
      void
      from_value_to_value(const Value<V>& from, Value<V>& to);



# ifndef MLN_INCLUDE_ONLY

      // Case 1:

      template <typename V, typename W>
      void
      from_value_to_value_(const mln::value::Vectorial<V>& from,
                                 mln::value::Vectorial<W>&  to)
      {
        exact(to) = exact(from).to_equiv();
      }

      // Case 2:

      template <typename V, typename W>
      void
      from_value_to_value_(const mln::value::Scalar<V>& from,
                                 mln::value::Scalar<W>&  to)
      {
        exact(to) = exact(from).to_equiv();
      }

      template <typename V, typename W>
      inline
      void
      from_value_to_value_(const Value<V>& from, Value<W>& to)
      {
        // No concept based conversion. Trying to find more specific
        // conversion with other from_to overloads.
        convert::over_load::from_to_(exact(from), exact(to));
      }


      // Facades.

      template <typename V, typename W>
      inline
      void
      from_value_to_value(const Value<V>& from, Value<W>& to)
      {
        from_value_to_value_(exact(from), exact(to));
      }

      template <typename V>
      inline
      void
      from_value_to_value(const Value<V>& from, Value<V>& to)
      {
        exact(to) = exact(from);
      }

# endif // ! MLN_INCLUDE_ONLY

    } // end of namespace mln::convert::impl

  } // end of namespace mln::convert

} // end of namespace mln


#endif // ! MLN_CONVERT_IMPL_FROM_VALUE_TO_VALUE_HH