RhodeCode

  namespace _maps_bits {

    template <typename Value>

    struct Identity {

      typedef Value argument_type;

      typedef Value result_type;

      Value operator()(const Value& val) const {

	return val;

      }

    };

    template <typename _Iterator, typename Enable = void>

    struct IteratorTraits {

      typedef typename std::iterator_traits<_Iterator>::value_type Value;

    };

    template <typename _Iterator>

    struct IteratorTraits<_Iterator,

      typename exists<typename _Iterator::container_type>::type>

    {

      typedef typename _Iterator::container_type::value_type Value;

    };

  }

  /// \brief Writable bool map for logging each \c true assigned element

  ///

  /// A \ref concepts::ReadWriteMap "read-write" bool map for logging

  /// each \c true assigned element, i.e it copies subsequently each

  /// keys set to \c true to the given iterator.

  ///

  /// \tparam It the type of the Iterator.

  /// \tparam Ke the type of the map's Key. The default value should

  /// work in most cases.

  ///

  /// \note The container of the iterator must contain enough space

  /// for the elements. (Or it should be an inserter iterator).

  ///

  /// \todo Revise the name of this class and give an example code.

  template <typename It,

	    typename Ke=typename _maps_bits::IteratorTraits<It>::Value>

  class StoreBoolMap {

  public:

    typedef It Iterator;

    typedef Ke Key;

    typedef bool Value;

    /// Constructor

    StoreBoolMap(Iterator it)

      : _begin(it), _end(it) {}

    /// Gives back the given iterator set for the first key

    Iterator begin() const {

      return _begin;

    }

    /// Gives back the the 'after the last' iterator

    Iterator end() const {

      return _end;

    }

    /// The set function of the map

    void set(const Key& key, Value value) const {

      if (value) {

	*_end++ = key;

      }

    }

  private:

    Iterator _begin;

    mutable Iterator _end;

  };