RhodeCode

    /// @{

    /// Readable map concept

    /// Readable map concept.

    ///

    template<typename K, typename T>

    class ReadMap

    {

    public:

      /// The key type of the map.

      typedef K Key;    

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

      typedef T Value;

      /// Returns the value associated with a key.

      /// Returns the value associated with a key.

      /// \bug Value shouldn't need to be default constructible.

      ///

      Value operator[](const Key &) const {return Value();}

      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(val);

	  ignore_unused_variable_warning(own_val);

	  ignore_unused_variable_warning(key);

	}

	Key& key;

	typename _ReadMap::Key& own_key;

	_ReadMap& m;

      };

    };

    /// Writable map concept

    /// Writable map concept.

    ///

    template<typename K, typename T>

    class WriteMap

    public:

      /// Tag for reference maps.

      typedef True ReferenceMapTag;

      /// The key type of the map.

      typedef K Key;    

      /// 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;

    protected:

      Value tmp;

    public:

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

      Reference operator[](const Key &) { return tmp; }

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

      ConstReference operator[](const Key &) const { return tmp; }

      /// Sets the value associated with a key.

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

      template<typename _ReferenceMap>

	void constraints() {

	  m[key] = val;

	  val  = m[key];

	  m[key] = ref;

	  ref = m[key];

	  m[own_key] = own_val;

	  own_val  = m[own_key];

	  m[own_key] = own_ref;

	  own_ref = m[own_key];	  	  

	}

	typename _ReferenceMap::Key& own_key;

	typename _ReferenceMap::Value& own_val;

	Key& key;

	Value& val;

	_ReferenceMap& m;

      };

    };

    // @}

  } //namespace concepts

} //namespace lemon

#endif // LEMON_CONCEPT_MAPS_H