boost/iterator.hpp

   1 //  interator.hpp workarounds for non-conforming standard libraries  ---------//
   2
   3 //  (C) Copyright Beman Dawes 2000. Distributed under the Boost
   4 //  Software License, Version 1.0. (See accompanying file
   5 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //  See http://www.boost.org/libs/utility for documentation.
   8
   9 //  Revision History
  10 //  12 Jan 01 added <cstddef> for std::ptrdiff_t (Jens Maurer)
  11 //  28 Jun 00 Workarounds to deal with known MSVC bugs (David Abrahams)
  12 //  26 Jun 00 Initial version (Jeremy Siek)
  13
  14 #ifndef BOOST_ITERATOR_HPP
  15 #define BOOST_ITERATOR_HPP
  16
  17 #include <iterator>
  18 #include <cstddef>           // std::ptrdiff_t
  19 #include <boost/config.hpp>
  20
  21 namespace boost
  22 {
  23 # if defined(BOOST_NO_STD_ITERATOR) && !defined(BOOST_MSVC_STD_ITERATOR)
  24   template <class Category, class T,
  25     class Distance = std::ptrdiff_t,
  26     class Pointer = T*, class Reference = T&>
  27   struct iterator
  28   {
  29     typedef T         value_type;
  30     typedef Distance  difference_type;
  31     typedef Pointer   pointer;
  32     typedef Reference reference;
  33     typedef Category  iterator_category;
  34   };
  35 # else
  36
  37   // declare iterator_base in namespace detail to work around MSVC bugs which
  38   // prevent derivation from an identically-named class in a different namespace.
  39   namespace detail {
  40    template <class Category, class T, class Distance, class Pointer, class Reference>
  41 #  if !defined(BOOST_MSVC_STD_ITERATOR)
  42    struct iterator_base : std::iterator<Category, T, Distance, Pointer, Reference> {};
  43 #  else
  44    struct iterator_base : std::iterator<Category, T, Distance>
  45    {
  46      typedef Reference reference;
  47      typedef Pointer pointer;
  48      typedef Distance difference_type;
  49    };
  50 #  endif
  51   }
  52
  53   template <class Category, class T, class Distance = std::ptrdiff_t,
  54             class Pointer = T*, class Reference = T&>
  55   struct iterator : boost::detail::iterator_base<Category, T, Distance, Pointer, Reference> {};
  56 # endif
  57 } // namespace boost
  58
  59 #endif // BOOST_ITERATOR_HPP