Rework reverse_iterator::operator[] so as not to use the base iterators operator [], which can cause constness problems. Fixes PR17883
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@231375 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/iterator b/include/iterator
index 04ff4c1..7f7e9ee 100644
--- a/include/iterator
+++ b/include/iterator
@@ -575,7 +575,7 @@
_LIBCPP_INLINE_VISIBILITY reverse_iterator& operator-=(difference_type __n)
{current += __n; return *this;}
_LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const
- {return current[-__n-1];}
+ {return *(*this + __n);}
};
template <class _Iter1, class _Iter2>