ceph/src/boost/libs/icl/include/boost/icl/iterator.hpp

   1 /*-----------------------------------------------------------------------------+
   2 Copyright (c) 2009-2009: Joachim Faulhaber
   3 +------------------------------------------------------------------------------+
   4    Distributed under the Boost Software License, Version 1.0.
   5       (See accompanying file LICENCE.txt or copy at
   6            http://www.boost.org/LICENSE_1_0.txt)
   7 +-----------------------------------------------------------------------------*/
   8 #ifndef BOOST_ICL_ITERATOR_HPP_JOFA_091003
   9 #define BOOST_ICL_ITERATOR_HPP_JOFA_091003
  10
  11 #include <iterator>
  12 #include <boost/config/warning_disable.hpp>
  13
  14 namespace boost{namespace icl
  15 {
  16
  17 /** \brief Performes an addition using a container's memberfunction add, when operator= is called. */
  18 template<class ContainerT> class add_iterator
  19     : public std::iterator<std::output_iterator_tag, void, void, void, void>
  20 {
  21 public:
  22     /// The container's type.
  23     typedef ContainerT container_type;
  24     typedef std::output_iterator_tag iterator_category;
  25
  26     /** An add_iterator is constructed with a container and a position
  27         that has to be maintained. */
  28     add_iterator(ContainerT& cont, typename ContainerT::iterator iter)
  29     : _cont(&cont), _iter(iter) {}
  30
  31     /** This assignment operator adds the \c value before the current position.
  32         It maintains it's position by incrementing after addition.    */
  33     add_iterator& operator=(typename ContainerT::const_reference value)
  34     {
  35         _iter = icl::add(*_cont, _iter, value);
  36         if(_iter != _cont->end())
  37             ++_iter;
  38         return *this;
  39     }
  40
  41     add_iterator& operator*()    { return *this; }
  42     add_iterator& operator++()   { return *this; }
  43     add_iterator& operator++(int){ return *this; }
  44
  45 private:
  46     ContainerT*                   _cont;
  47     typename ContainerT::iterator _iter;
  48 };
  49
  50
  51 /** Function adder creates and initializes an add_iterator */
  52 template<class ContainerT, typename IteratorT>
  53 inline add_iterator<ContainerT> adder(ContainerT& cont, IteratorT iter_)
  54 {
  55     return add_iterator<ContainerT>(cont, typename ContainerT::iterator(iter_));
  56 }
  57
  58 /** \brief Performes an insertion using a container's memberfunction add, when operator= is called. */
  59 template<class ContainerT> class insert_iterator
  60     : public std::iterator<std::output_iterator_tag, void, void, void, void>
  61 {
  62 public:
  63     /// The container's type.
  64     typedef ContainerT container_type;
  65     typedef std::output_iterator_tag iterator_category;
  66
  67     /** An insert_iterator is constructed with a container and a position
  68         that has to be maintained. */
  69     insert_iterator(ContainerT& cont, typename ContainerT::iterator iter)
  70     : _cont(&cont), _iter(iter) {}
  71
  72     /** This assignment operator adds the \c value before the current position.
  73         It maintains it's position by incrementing after addition.    */
  74     insert_iterator& operator=(typename ContainerT::const_reference value)
  75     {
  76         _iter = _cont->insert(_iter, value);
  77         if(_iter != _cont->end())
  78             ++_iter;
  79         return *this;
  80     }
  81
  82     insert_iterator& operator*()    { return *this; }
  83     insert_iterator& operator++()   { return *this; }
  84     insert_iterator& operator++(int){ return *this; }
  85
  86 private:
  87     ContainerT*                   _cont;
  88     typename ContainerT::iterator _iter;
  89 };
  90
  91
  92 /** Function inserter creates and initializes an insert_iterator */
  93 template<class ContainerT, typename IteratorT>
  94 inline insert_iterator<ContainerT> inserter(ContainerT& cont, IteratorT iter_)
  95 {
  96     return insert_iterator<ContainerT>(cont, typename ContainerT::iterator(iter_));
  97 }
  98
  99 }} // namespace icl boost
 100
 101 #endif // BOOST_ICL_ITERATOR_HPP_JOFA_091003
 102
 103