/* -*- mode: C++; indent-tabs-mode: nil; -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library.

 *

 * Copyright (C) 2003-2009

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#ifndef LEMON_CONCEPTS_MAPS_H

#define LEMON_CONCEPTS_MAPS_H

#include <lemon/core.h>

#include <lemon/concept_check.h>

///\ingroup map_concepts

///\file

///\brief The concept of maps.

namespace lemon {

  namespace concepts {

    /// \addtogroup map_concepts

    /// @{

    /// Readable map concept

    /// Readable map concept.

    ///

    template<typename K, typename T>

    class ReadMap

    {

    public:

      /// The key type of the map.

      typedef K Key;

      /// \brief The value type of the map.

      /// (The type of objects associated with the keys).

      typedef T Value;

      /// Returns the value associated with the given key.

      Value operator[](const Key &) const {

        return *static_cast<Value *>(0);

      }

      template<typename _ReadMap>

      struct Constraints {

        void constraints() {

          Value val = m[key];

          val = m[key];

          typename _ReadMap::Value own_val = m[own_key];

          own_val = m[own_key];

          ignore_unused_variable_warning(key);

          ignore_unused_variable_warning(val);

          ignore_unused_variable_warning(own_key);

          ignore_unused_variable_warning(own_val);

        }

        const Key& key;

        const typename _ReadMap::Key& own_key;

        const _ReadMap& m;

        Constraints() {}

      };

    };

    /// Writable map concept

    /// Writable map concept.

    ///

    template<typename K, typename T>

    class WriteMap

    {

    public:

      /// The key type of the map.

      typedef K Key;

      /// \brief The value type of the map.

      /// (The type of objects associated with the keys).

      typedef T Value;

      /// Sets the value associated with the given key.

      void set(const Key &, const Value &) {}

      /// Default constructor.

      WriteMap() {}

      template <typename _WriteMap>

      struct Constraints {

        void constraints() {

          m.set(key, val);

          m.set(own_key, own_val);

          ignore_unused_variable_warning(key);

          ignore_unused_variable_warning(val);

          ignore_unused_variable_warning(own_key);

          ignore_unused_variable_warning(own_val);

        }

        const Key& key;

        const Value& val;

        const typename _WriteMap::Key& own_key;

        const typename _WriteMap::Value& own_val;

        _WriteMap& m;

        Constraints() {}

      };

    };

    /// Read/writable map concept

    /// Read/writable map concept.

    ///

    template<typename K, typename T>

    class ReadWriteMap : public ReadMap<K,T>,

                         public WriteMap<K,T>

    {

    public:

      /// The key type of the map.

      typedef K Key;

      /// \brief The value type of the map.

      /// (The type of objects associated with the keys).

      typedef T Value;

      /// Returns the value associated with the given key.

      Value operator[](const Key &) const {

        Value *r = 0;

        return *r;

      }

      /// Sets the value associated with the given key.

      void set(const Key &, const Value &) {}

      template<typename _ReadWriteMap>

      struct Constraints {

        void constraints() {

          checkConcept<ReadMap<K, T>, _ReadWriteMap >();

          checkConcept<WriteMap<K, T>, _ReadWriteMap >();

        }

      };

    };

    /// Dereferable map concept

    /// Dereferable map concept.

    ///

    template<typename K, typename T, typename R, typename CR>

    class ReferenceMap : public ReadWriteMap<K,T>

    {

    public:

      /// Tag for reference maps.

      typedef True ReferenceMapTag;

      /// The key type of the map.

      typedef K Key;

      /// \brief The value type of the map.

      /// (The type of objects associated with the keys).

      typedef T Value;

      /// The reference type of the map.

      typedef R Reference;

      /// The const reference type of the map.

      typedef CR ConstReference;

    public:

      /// Returns a reference to the value associated with the given key.

      Reference operator[](const Key &) {

        Value *r = 0;

        return *r;

      }

      /// Returns a const reference to the value associated with the given key.

      ConstReference operator[](const Key &) const {

        Value *r = 0;

        return *r;

      }

      /// Sets the value associated with the given key.

      void set(const Key &k,const Value &t) { operator[](k)=t; }

      template<typename _ReferenceMap>

      struct Constraints {

        typename enable_if<typename _ReferenceMap::ReferenceMapTag, void>::type

        constraints() {

          checkConcept<ReadWriteMap<K, T>, _ReferenceMap >();

          ref = m[key];

          m[key] = val;

          m[key] = ref;

          m[key] = cref;

          own_ref = m[own_key];

          m[own_key] = own_val;

          m[own_key] = own_ref;

          m[own_key] = own_cref;

          m[key] = m[own_key];

          m[own_key] = m[key];

        }

        const Key& key;

        Value& val;

        Reference ref;

        ConstReference cref;

        const typename _ReferenceMap::Key& own_key;

        typename _ReferenceMap::Value& own_val;

        typename _ReferenceMap::Reference own_ref;

        typename _ReferenceMap::ConstReference own_cref;

        _ReferenceMap& m;

        Constraints() {}

      };

    };

    // @}

  } //namespace concepts

} //namespace lemon

#endif