sum.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_MATH_SUM_HH
# define MLN_ACCU_MATH_SUM_HH


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

# include <mln/util/pix.hh> // To prevent accu::math::sum to work on pixels (ambiguous).

# include <mln/trait/value_.hh>      // For mln_sum.
# include <mln/value/builtin/all.hh> // In the case of summing builtin values.
# include <mln/literal/zero.hh>      // For initialization.


namespace mln
{

  namespace accu
  {

    namespace math
    {

      // Forward declaration.
      template <typename T, typename S>
      struct sum;

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

    namespace meta
    {

      namespace math
      {

        struct sum : public Meta_Accumulator< sum >
        {
          template <typename T, typename S = mln_sum(T)>
          struct with
          {
            typedef accu::math::sum<T, S> ret;
          };
        };

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

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

  } // end of namespace mln::accu

  // Traits.
  namespace trait
  {

    template <typename T, typename S>
    struct accumulator_< accu::math::sum<T,S> >
    {
      typedef accumulator::has_untake::yes    has_untake;
      typedef accumulator::has_set_value::yes has_set_value;
      typedef accumulator::has_stop::no       has_stop;
      typedef accumulator::when_pix::not_ok   when_pix;
    };

  } // end of namespace mln::trait


  namespace accu
  {

    namespace math
    {

      //
      template <typename T, typename S = mln_sum(T)>
      struct sum : public mln::accu::internal::base< const S&, sum<T,S> >
      {
        typedef T argument;

        sum();

        void init();
        void take(const argument& t);
        void take_as_init_(const argument& t);
        void take(const sum<T,S>& other);

        void untake(const argument& t);
        void untake(const sum<T,S>& other);
        void set_value(const S& s);

        const S& to_result() const;

        bool is_valid() const;

      protected:

        S s_;
      };


      template <typename I, typename S>
      struct sum< util::pix<I>, S >;


# ifndef MLN_INCLUDE_ONLY



      template <typename T, typename S>
      inline
      sum<T,S>::sum()
      {
        init();
      }

      template <typename T, typename S>
      inline
      void
      sum<T,S>::init()
      {
        s_ = literal::zero;
      }

      template <typename T, typename S>
      inline
      void sum<T,S>::take(const argument& t)
      {
        s_ += static_cast<S>(t);
      }

      template <typename T, typename S>
      inline
      void sum<T,S>::untake(const argument& t)
      {
        s_ -= static_cast<S>(t);
      }

      template <typename T, typename S>
      inline
      void sum<T,S>::take_as_init_(const argument& t)
      {
        s_ = static_cast<S>(t);
      }

      template <typename T, typename S>
      inline
      void
      sum<T,S>::take(const sum<T,S>& other)
      {
        s_ += other.s_;
      }

      template <typename T, typename S>
      inline
      void
      sum<T,S>::untake(const sum<T,S>& other)
      {
        s_ -= other.s_;
      }

      template <typename T, typename S>
      inline
      const S&
      sum<T,S>::to_result() const
      {
        return s_;
      }

      template <typename T, typename S>
      inline
      void
      sum<T,S>::set_value(const S& s)
      {
        s_ = s;
      }

      template <typename T, typename S>
      inline
      bool
      sum<T,S>::is_valid() const
      {
        return true;
      }

# endif // ! MLN_INCLUDE_ONLY

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

  } // end of namespace mln::accu

} // end of namespace mln


#endif // ! MLN_ACCU_MATH_SUM_HH

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