Make next/prev/advance/distance operations on iterators be constexpr. I missed this when I implemented the rest of P0031R0 git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@303281 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/iterator b/include/iterator index 47a7811..4aa4474 100644 --- a/include/iterator +++ b/include/iterator
@@ -64,14 +64,23 @@ struct bidirectional_iterator_tag : public forward_iterator_tag {}; struct random_access_iterator_tag : public bidirectional_iterator_tag {}; +// 27.4.3, iterator operations // extension: second argument not conforming to C++03 -template <class InputIterator> -void advance(InputIterator& i, +template <class InputIterator> // constexpr in C++17 + constexpr void advance(InputIterator& i, typename iterator_traits<InputIterator>::difference_type n); -template <class InputIterator> -typename iterator_traits<InputIterator>::difference_type -distance(InputIterator first, InputIterator last); +template <class InputIterator> // constexpr in C++17 + constexpr typename iterator_traits<InputIterator>::difference_type + distance(InputIterator first, InputIterator last); + +template <class InputIterator> // constexpr in C++17 + constexpr InputIterator next(InputIterator x, +typename iterator_traits<InputIterator>::difference_type n = 1); + +template <class BidirectionalIterator> // constexpr in C++17 + constexpr BidirectionalIterator prev(BidirectionalIterator x, + typename iterator_traits<BidirectionalIterator>::difference_type n = 1); template <class Iterator> class reverse_iterator @@ -529,7 +538,7 @@ }; template <class _InputIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 void __advance(_InputIter& __i, typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag) { @@ -538,7 +547,7 @@ } template <class _BiDirIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 void __advance(_BiDirIter& __i, typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag) { @@ -551,7 +560,7 @@ } template <class _RandIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 void __advance(_RandIter& __i, typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag) { @@ -559,7 +568,7 @@ } template <class _InputIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 void advance(_InputIter& __i, typename iterator_traits<_InputIter>::difference_type __n) { @@ -567,7 +576,7 @@ } template <class _InputIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 typename iterator_traits<_InputIter>::difference_type __distance(_InputIter __first, _InputIter __last, input_iterator_tag) { @@ -578,7 +587,7 @@ } template <class _RandIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 typename iterator_traits<_RandIter>::difference_type __distance(_RandIter __first, _RandIter __last, random_access_iterator_tag) { @@ -586,7 +595,7 @@ } template <class _InputIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 typename iterator_traits<_InputIter>::difference_type distance(_InputIter __first, _InputIter __last) { @@ -594,7 +603,7 @@ } template <class _InputIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _InputIter next(_InputIter __x, typename iterator_traits<_InputIter>::difference_type __n = 1, @@ -605,7 +614,7 @@ } template <class _BidiretionalIter> -inline _LIBCPP_INLINE_VISIBILITY +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _BidiretionalIter prev(_BidiretionalIter __x, typename iterator_traits<_BidiretionalIter>::difference_type __n = 1, 