RhodeCode

    /// Readable map concept

    /// Readable map concept.

    ///

    template<typename K, typename T>

    class ReadMap

    {

    public:

      typedef K Key;    

      typedef T Value;

      /// Returns the value associated with a key.

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

      ///

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

    /// Writable map concept

    /// Writable map concept.

    ///

    template<typename K, typename T>

    class WriteMap

    {

    public:

      typedef K Key;    

      typedef T Value;

      /// Sets the value associated with a key.

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

      ///Default constructor

      WriteMap() {}

    };

    /// Read/Writable map concept

    /// Read/writable map concept.

    ///

    template<typename K, typename T>

    class ReadWriteMap : public ReadMap<K,T>,

    {

    public:

      typedef K Key;    

      typedef T Value;

      /// Returns the value associated with a key.

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

      /// Sets the value associated with a key.

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

      template<typename _ReadWriteMap>

    /// 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;

      typedef K Key;    

      typedef T Value;

      typedef R Reference;

      typedef CR ConstReference;

    protected:

      Value tmp;

    public:

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

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