[range] - Fix for the demotion of traversal tags supplied by aschoedl. This is mentioned in Trac issue 5061, but has also been reported independently by a few users.

[SVN r70040]
This commit is contained in:
Neil Groves
2011-03-16 23:47:02 +00:00
parent cc8a1413cb
commit c6a6a46db4

View File

@ -5,6 +5,9 @@
// 1.0. (See accompanying file LICENSE_1_0.txt or copy at // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt) // http://www.boost.org/LICENSE_1_0.txt)
// //
// Acknowledgements:
// aschoedl supplied a fix to supply the level of interoperability I had
// originally intended, but failed to implement.
// //
// For more information, see http://www.boost.org/libs/range/ // For more information, see http://www.boost.org/libs/range/
// //
@ -19,12 +22,12 @@ namespace boost
{ {
template<class IteratorTraversalTag1, class IteratorTraversalTag2> template<class IteratorTraversalTag1, class IteratorTraversalTag2>
struct demote_iterator_traversal_tag struct inner_demote_iterator_traversal_tag
{ {
}; };
#define BOOST_DEMOTE_TRAVERSAL_TAG( Tag1, Tag2, ResultTag ) \ #define BOOST_DEMOTE_TRAVERSAL_TAG( Tag1, Tag2, ResultTag ) \
template<> struct demote_iterator_traversal_tag< Tag1 , Tag2 > \ template<> struct inner_demote_iterator_traversal_tag< Tag1 , Tag2 > \
{ \ { \
typedef ResultTag type; \ typedef ResultTag type; \
}; };
@ -73,6 +76,15 @@ BOOST_DEMOTE_TRAVERSAL_TAG( random_access_traversal_tag, random_access_traversal
#undef BOOST_DEMOTE_TRAVERSAL_TAG #undef BOOST_DEMOTE_TRAVERSAL_TAG
template<class IteratorTraversalTag1, class IteratorTraversalTag2>
struct demote_iterator_traversal_tag
: inner_demote_iterator_traversal_tag<
typename boost::detail::pure_traversal_tag< IteratorTraversalTag1 >::type,
typename boost::detail::pure_traversal_tag< IteratorTraversalTag2 >::type
>
{
};
} // namespace range_detail } // namespace range_detail
} // namespace boost } // namespace boost