from_double_to_value.hh

// Copyright (C) 2009, 2010 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_DOUBLE_TO_VALUE_HH
# define MLN_CONVERT_IMPL_FROM_DOUBLE_TO_VALUE_HH


# include <utility>
# include <mln/value/concept/integer.hh>
# include <mln/value/concept/floating.hh>
# include <mln/core/concept/value.hh>
# include <mln/math/round.hh>




namespace mln
{

  namespace convert
  {

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


# ifndef MLN_INCLUDE_ONLY

      namespace impl
      {

        // Case 1:

        template <typename V>
        inline
        void
        from_double_to_value(const double&          from,
                            mln::value::Integer<V>& to)
        {
          exact(to) = math::round<V>()(from);
        }

        // Case 2:

        template <typename V>
        inline
        void
        from_double_to_value(const double&            from,
                            mln::value::Floating<V>&  to)
        {
          exact(to) = from;
        }


        // Default: no conversion defined.

        template <typename V>
        inline
        void
        from_double_to_value(const double&            /* from */,
                             Value<V>&                /* to */)
        {
          mlc_abort(V)::check();
        }

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


      namespace internal
      {

        template <typename V>
        inline
        void
        from_double_to_value_dispatch(const double& from, Value<V>& to)
        {
          impl::from_double_to_value(from, exact(to));
        }

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


      namespace over_load
      {

        // Facades.


        // double-> Value
        template <typename V>
        inline
        void
        from_to_(const double& from, Value<V>& to)
        {
          internal::from_double_to_value_dispatch(from, to);
        }

        // double-> unsigned
        inline
        void
        from_to_(const double&      from,
                 unsigned&          to)
        {
          mln_precondition(from >= 0);
          to = math::round<unsigned>()(from);
        }

        // double-> int
        inline
        void
        from_to_(const double&      from,
                 int&               to)
        {
          to = math::round<int>()(from);
        }

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

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::convert

} // end of namespace mln


#endif // ! MLN_CONVERT_IMPL_FROM_DOUBLE_TO_VALUE_HH