card.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_SET_CARD_HH
# define MLN_SET_CARD_HH


# include <mln/core/concept/site_set.hh>


namespace mln
{

  namespace set
  {

    template <typename S>
    unsigned card(const Site_Set<S>& s);


# ifndef MLN_INCLUDE_ONLY


    // Implementations.

    namespace impl
    {

      // Generic version.

      namespace generic
      {

        template <typename S>
        unsigned card(const Site_Set<S>& s_)
        {
          trace::entering("set::impl::generic::card");
          const S& s = exact(s_);
          mln_precondition(s.is_valid());

          unsigned n = 0;
          mln_piter(S) p(s);
          for_all(p)
            ++n;

          trace::exiting("set::impl::generic::card");
          return n;
        }

      } // end of namespace mln::set::impl::generic


      // A single specialization.

      template <typename S>
      inline
      unsigned card_from_method(const Site_Set<S>& s)
      {
        trace::entering("set::impl::card_from_method");
        unsigned n = exact(s).nsites();
        trace::exiting("set::impl::card_from_method");
        return n;
      }

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



    // Dispatch.

    namespace internal
    {

      template <typename S>
      inline
      unsigned card_dispatch(mln::trait::site_set::nsites::any,
                             const Site_Set<S>& s)
      {
        return impl::generic::card(s);
      }

      template <typename S>
      inline
      unsigned card_dispatch(mln::trait::site_set::nsites::known,
                             const Site_Set<S>& s)
      {
        return impl::card_from_method(s);
      }

      // Dispatch facade.

      template <typename S>
      inline
      unsigned card_dispatch(const Site_Set<S>& s)
      {
        return card_dispatch(mln_trait_site_set_nsites(S)(),
                             s);
      }

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



    // Facade.

    template <typename S>
    inline
    unsigned card(const Site_Set<S>& s)
    {
      trace::entering("set::card");
      mln_precondition(exact(s).is_valid());

      unsigned n = internal::card_dispatch(s);

      trace::exiting("set::card");
      return n;
    }

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::set

} // end of namespace mln


#endif // ! MLN_SET_CARD_HH