diff options
Diffstat (limited to 'libcxx/include/__iterator/advance.h')
| -rw-r--r-- | libcxx/include/__iterator/advance.h | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/libcxx/include/__iterator/advance.h b/libcxx/include/__iterator/advance.h index 64c8d249f78f..73473f899eac 100644 --- a/libcxx/include/__iterator/advance.h +++ b/libcxx/include/__iterator/advance.h @@ -65,8 +65,9 @@ template < class _InputIter, _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 void advance(_InputIter& __i, _Distance __orig_n) { typedef typename iterator_traits<_InputIter>::difference_type _Difference; _Difference __n = static_cast<_Difference>(std::__convert_to_integral(__orig_n)); - _LIBCPP_ASSERT_UNCATEGORIZED(__n >= 0 || __has_bidirectional_iterator_category<_InputIter>::value, - "Attempt to advance(it, n) with negative n on a non-bidirectional iterator"); + // Calling `advance` with a negative value on a non-bidirectional iterator is a no-op in the current implementation. + _LIBCPP_ASSERT_PEDANTIC(__n >= 0 || __has_bidirectional_iterator_category<_InputIter>::value, + "Attempt to advance(it, n) with negative n on a non-bidirectional iterator"); std::__advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category()); } @@ -99,7 +100,8 @@ public: // Preconditions: If `I` does not model `bidirectional_iterator`, `n` is not negative. template <input_or_output_iterator _Ip> _LIBCPP_HIDE_FROM_ABI constexpr void operator()(_Ip& __i, iter_difference_t<_Ip> __n) const { - _LIBCPP_ASSERT_UNCATEGORIZED( + // Calling `advance` with a negative value on a non-bidirectional iterator is a no-op in the current implementation. + _LIBCPP_ASSERT_PEDANTIC( __n >= 0 || bidirectional_iterator<_Ip>, "If `n < 0`, then `bidirectional_iterator<I>` must be true."); // If `I` models `random_access_iterator`, equivalent to `i += n`. @@ -149,8 +151,9 @@ public: template <input_or_output_iterator _Ip, sentinel_for<_Ip> _Sp> _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Ip> operator()(_Ip& __i, iter_difference_t<_Ip> __n, _Sp __bound_sentinel) const { - _LIBCPP_ASSERT_UNCATEGORIZED((__n >= 0) || (bidirectional_iterator<_Ip> && same_as<_Ip, _Sp>), - "If `n < 0`, then `bidirectional_iterator<I> && same_as<I, S>` must be true."); + // Calling `advance` with a negative value on a non-bidirectional iterator is a no-op in the current implementation. + _LIBCPP_ASSERT_PEDANTIC((__n >= 0) || (bidirectional_iterator<_Ip> && same_as<_Ip, _Sp>), + "If `n < 0`, then `bidirectional_iterator<I> && same_as<I, S>` must be true."); // If `S` and `I` model `sized_sentinel_for<S, I>`: if constexpr (sized_sentinel_for<_Sp, _Ip>) { // If |n| >= |bound_sentinel - i|, equivalent to `ranges::advance(i, bound_sentinel)`. |