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Boost.Range defect fix for the operator[] of iterator_range. This now reverts to a simpler implementation when the iterator is a pointer.

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[SVN r61258]
This commit is contained in:
Neil Groves
2010-04-13 20:41:11 +00:00
parent 350a1f8bfc
commit 47b40f66e1
3 changed files with 77 additions and 8 deletions
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45
include/boost/range/iterator_range_core.hpp
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@ -298,14 +298,22 @@ namespace boost
return m_Begin[at];
}
#else
BOOST_DEDUCED_TYPENAME boost::detail::operator_brackets_result<iterator, value_type, reference>::type
operator[]( difference_type at ) const
{
BOOST_ASSERT( at >= 0 && at < size() );
typedef boost::detail::use_operator_brackets_proxy<value_type,reference> use_proxy;
return boost::detail::make_operator_brackets_result<iterator>(m_Begin + at, use_proxy());
}
// Using the operator_brackets_result mechanism properly supports
// the corner cases with proxies for references etc. However
// the operator_brackets_result implementation does not support
// pointers as iterators. Since a pointer can't have the
// issues with proxies this implementation uses a simpler
// implementation if the iterator is a pointer.
BOOST_DEDUCED_TYPENAME boost::mpl::if_<
boost::is_pointer<iterator>,
reference,
BOOST_DEDUCED_TYPENAME boost::detail::operator_brackets_result<iterator, value_type, reference>::type
>::type
operator[]( difference_type at ) const
{
BOOST_ASSERT( at >= 0 && at < size() );
return get_at(m_Begin, at);
}
#endif
//
@ -332,6 +340,27 @@ namespace boost
}
private:
template<class Iterator>
static BOOST_DEDUCED_TYPENAME boost::enable_if<
boost::is_pointer<Iterator>,
reference
>::type
get_at( Iterator it, difference_type at )
{
return it[at];
}
template<class Iterator>
static BOOST_DEDUCED_TYPENAME boost::disable_if<
boost::is_pointer<Iterator>,
BOOST_DEDUCED_TYPENAME boost::detail::operator_brackets_result<Iterator, value_type, reference>::type
>::type
get_at( Iterator it, difference_type at )
{
typedef boost::detail::use_operator_brackets_proxy<value_type,reference> use_proxy;
return boost::detail::make_operator_brackets_result<Iterator>(it + at, use_proxy());
}
// begin and end iterators
IteratorT m_Begin;
IteratorT m_End;