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