diff options
Diffstat (limited to 'libcxx/include/iterator')
| -rw-r--r-- | libcxx/include/iterator | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/libcxx/include/iterator b/libcxx/include/iterator index 16c1bcb76c8..5846c1b494f 100644 --- a/libcxx/include/iterator +++ b/libcxx/include/iterator @@ -584,6 +584,8 @@ inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 void advance(_InputIter& __i, typename iterator_traits<_InputIter>::difference_type __n) { + _LIBCPP_ASSERT(__n >= 0 || __is_bidirectional_iterator<_InputIter>::value, + "Attempt to advance(it, -n) on a non-bidi iterator"); __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category()); } @@ -624,20 +626,25 @@ typename enable_if next(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1) { + _LIBCPP_ASSERT(__n >= 0 || __is_bidirectional_iterator<_InputIter>::value, + "Attempt to next(it, -n) on a non-bidi iterator"); + _VSTD::advance(__x, __n); return __x; } -template <class _BidirectionalIter> +template <class _InputIter> inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 typename enable_if < - __is_bidirectional_iterator<_BidirectionalIter>::value, - _BidirectionalIter + __is_input_iterator<_InputIter>::value, + _InputIter >::type -prev(_BidirectionalIter __x, - typename iterator_traits<_BidirectionalIter>::difference_type __n = 1) +prev(_InputIter __x, + typename iterator_traits<_InputIter>::difference_type __n = 1) { + _LIBCPP_ASSERT(__n <= 0 || __is_bidirectional_iterator<_InputIter>::value, + "Attempt to prev(it, +n) on a non-bidi iterator"); _VSTD::advance(__x, -__n); return __x; } |
