/* -*- 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