//  interator.hpp workarounds for non-conforming standard libraries  ---------//
 
 //  (C) Copyright Beman Dawes 2000. Distributed under the Boost
 //  Software License, Version 1.0. (See accompanying file
 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
 //  See http://www.boost.org/libs/utility for documentation.
 
 //  Revision History
 //  12 Jan 01 added <cstddef> for std::ptrdiff_t (Jens Maurer)
 //  28 Jun 00 Workarounds to deal with known MSVC bugs (David Abrahams)
 //  26 Jun 00 Initial version (Jeremy Siek)
 
 #ifndef BOOST_ITERATOR_HPP
 #define BOOST_ITERATOR_HPP
 
 #include <iterator>
 #include <cstddef>           // std::ptrdiff_t
 #include <boost/config.hpp>
 
 namespace boost
 {
 # if defined(BOOST_NO_STD_ITERATOR) && !defined(BOOST_MSVC_STD_ITERATOR)
   template <class Category, class T,
     class Distance = std::ptrdiff_t,
     class Pointer = T*, class Reference = T&>
   struct iterator
   {
     typedef T         value_type;
     typedef Distance  difference_type;
     typedef Pointer   pointer;
     typedef Reference reference;
     typedef Category  iterator_category;
   };
 # else
 
   // declare iterator_base in namespace detail to work around MSVC bugs which
   // prevent derivation from an identically-named class in a different namespace.
   namespace detail {
    template <class Category, class T, class Distance, class Pointer, class Reference>
 #  if !defined(BOOST_MSVC_STD_ITERATOR)
    struct iterator_base : std::iterator<Category, T, Distance, Pointer, Reference> {};
 #  else
    struct iterator_base : std::iterator<Category, T, Distance>
    {
      typedef Reference reference;
      typedef Pointer pointer;
      typedef Distance difference_type;
    };
 #  endif
   }
 
   template <class Category, class T, class Distance = std::ptrdiff_t,
             class Pointer = T*, class Reference = T&>
   struct iterator : boost::detail::iterator_base<Category, T, Distance, Pointer, Reference> {};
 # endif
 } // namespace boost
 
 #endif // BOOST_ITERATOR_HPP