land.hh

// Copyright (C) 2007, 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_ACCU_LOGIC_LAND_HH
# define MLN_ACCU_LOGIC_LAND_HH


# include <mln/core/concept/meta_accumulator.hh>
# include <mln/accu/internal/base.hh>


namespace mln
{

  namespace accu
  {

    namespace logic
    {
      // Forward declaration.
      struct land;
    }

    namespace meta
    {
      namespace logic
      {

        struct land : public Meta_Accumulator< land >
        {
          template <typename T>
          struct with
          {
            typedef accu::logic::land ret;
          };
        };

      } // end of namespace mln::accu::meta::logic
    } // end of namespace mln::accu::meta

    namespace logic
    {

      //
      struct land : public mln::accu::internal::base< bool, land >
      {
        typedef bool argument;

        land();

        void init();
        void take_as_init_(const argument& t);

        void take(const argument& t);
        void take(const land& other);

        void untake(const argument& t);
        void untake(const land& other);

        bool to_result() const;

        bool is_valid() const;

      protected:
        unsigned nfalse_;
      };


# ifndef MLN_INCLUDE_ONLY

      inline
      land::land()
      {
        init();
      }

      inline
      void
      land::init()
      {
        nfalse_ = 0;
      }

      inline
      void land::take_as_init_(const argument& t)
      {
        nfalse_ = t ? 0 : 1;
      }

      inline
      void land::take(const argument& t)
      {
        if (t == false)
          ++nfalse_;
      }

      inline
      void
      land::take(const land& other)
      {
        nfalse_ += other.nfalse_;
      }

      inline
      void land::untake(const argument& t)
      {
        if (t == false)
          --nfalse_;
      }

      inline
      void
      land::untake(const land& other)
      {
        mln_precondition(other.nfalse_ <= nfalse_);
        nfalse_ -= other.nfalse_;
      }

      inline
      bool
      land::to_result() const
      {
        return nfalse_ == 0;
      }

      inline
      bool
      land::is_valid() const
      {
        return true;
      }

# endif // ! MLN_INCLUDE_ONLY

    } // end of namespace mln::accu::logic
  } // end of namespace mln::accu
} // end of namespace mln

#endif // ! MLN_ACCU_LOGIC_LAND_HH