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Diffstat (limited to 'lib/libcxx/include/__iterator/reverse_iterator.h')
| -rw-r--r-- | lib/libcxx/include/__iterator/reverse_iterator.h | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/lib/libcxx/include/__iterator/reverse_iterator.h b/lib/libcxx/include/__iterator/reverse_iterator.h new file mode 100644 index 0000000000..76424a89a1 --- /dev/null +++ b/lib/libcxx/include/__iterator/reverse_iterator.h @@ -0,0 +1,239 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef _LIBCPP___ITERATOR_REVERSE_ITERATOR_H +#define _LIBCPP___ITERATOR_REVERSE_ITERATOR_H + +#include <__config> +#include <__iterator/iterator.h> +#include <__iterator/iterator_traits.h> +#include <__memory/addressof.h> +#include <type_traits> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +template <class _Tp, class = void> +struct __is_stashing_iterator : false_type {}; + +template <class _Tp> +struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type> + : true_type {}; + +_LIBCPP_SUPPRESS_DEPRECATED_PUSH +template <class _Iter> +class _LIBCPP_TEMPLATE_VIS reverse_iterator +#if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES) + : public iterator<typename iterator_traits<_Iter>::iterator_category, + typename iterator_traits<_Iter>::value_type, + typename iterator_traits<_Iter>::difference_type, + typename iterator_traits<_Iter>::pointer, + typename iterator_traits<_Iter>::reference> +#endif +{ +_LIBCPP_SUPPRESS_DEPRECATED_POP +private: +#ifndef _LIBCPP_ABI_NO_ITERATOR_BASES + _Iter __t; // no longer used as of LWG #2360, not removed due to ABI break +#endif + + static_assert(!__is_stashing_iterator<_Iter>::value, + "The specified iterator type cannot be used with reverse_iterator; " + "Using stashing iterators with reverse_iterator causes undefined behavior"); + +protected: + _Iter current; +public: + typedef _Iter iterator_type; + typedef typename iterator_traits<_Iter>::difference_type difference_type; + typedef typename iterator_traits<_Iter>::reference reference; + typedef typename iterator_traits<_Iter>::pointer pointer; + typedef _If<__is_cpp17_random_access_iterator<_Iter>::value, + random_access_iterator_tag, + typename iterator_traits<_Iter>::iterator_category> iterator_category; + typedef typename iterator_traits<_Iter>::value_type value_type; + +#if _LIBCPP_STD_VER > 17 + typedef _If<__is_cpp17_random_access_iterator<_Iter>::value, + random_access_iterator_tag, + bidirectional_iterator_tag> iterator_concept; +#endif + +#ifndef _LIBCPP_ABI_NO_ITERATOR_BASES + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator() : __t(), current() {} + + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {} + + template <class _Up, class = _EnableIf< + !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value + > > + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator(const reverse_iterator<_Up>& __u) + : __t(__u.base()), current(__u.base()) + { } + + template <class _Up, class = _EnableIf< + !is_same<_Up, _Iter>::value && + is_convertible<_Up const&, _Iter>::value && + is_assignable<_Up const&, _Iter>::value + > > + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator& operator=(const reverse_iterator<_Up>& __u) { + __t = current = __u.base(); + return *this; + } +#else + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator() : current() {} + + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + explicit reverse_iterator(_Iter __x) : current(__x) {} + + template <class _Up, class = _EnableIf< + !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value + > > + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator(const reverse_iterator<_Up>& __u) + : current(__u.base()) + { } + + template <class _Up, class = _EnableIf< + !is_same<_Up, _Iter>::value && + is_convertible<_Up const&, _Iter>::value && + is_assignable<_Up const&, _Iter>::value + > > + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator& operator=(const reverse_iterator<_Up>& __u) { + current = __u.base(); + return *this; + } +#endif + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + _Iter base() const {return current;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reference operator*() const {_Iter __tmp = current; return *--__tmp;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + pointer operator->() const {return _VSTD::addressof(operator*());} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator& operator++() {--current; return *this;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator& operator--() {++current; return *this;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator operator+ (difference_type __n) const {return reverse_iterator(current - __n);} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator operator- (difference_type __n) const {return reverse_iterator(current + __n);} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;} + _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 + reference operator[](difference_type __n) const {return *(*this + __n);} +}; + +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +bool +operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __x.base() == __y.base(); +} + +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +bool +operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __x.base() > __y.base(); +} + +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +bool +operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __x.base() != __y.base(); +} + +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +bool +operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __x.base() < __y.base(); +} + +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +bool +operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __x.base() <= __y.base(); +} + +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +bool +operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __x.base() >= __y.base(); +} + +#ifndef _LIBCPP_CXX03_LANG +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +auto +operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +-> decltype(__y.base() - __x.base()) +{ + return __y.base() - __x.base(); +} +#else +template <class _Iter1, class _Iter2> +inline _LIBCPP_INLINE_VISIBILITY +typename reverse_iterator<_Iter1>::difference_type +operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y) +{ + return __y.base() - __x.base(); +} +#endif + +template <class _Iter> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +reverse_iterator<_Iter> +operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x) +{ + return reverse_iterator<_Iter>(__x.base() - __n); +} + +#if _LIBCPP_STD_VER > 11 +template <class _Iter> +inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 +reverse_iterator<_Iter> make_reverse_iterator(_Iter __i) +{ + return reverse_iterator<_Iter>(__i); +} +#endif + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___ITERATOR_REVERSE_ITERATOR_H |
