//===----------------------------------------------------------------------===//
//
// 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___ALGORITHM_ITERATOR_OPERATIONS_H
#define _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H
#include <__algorithm/iter_swap.h>
#include <__algorithm/ranges_iterator_concept.h>
#include <__assert>
#include <__config>
#include <__iterator/advance.h>
#include <__iterator/distance.h>
#include <__iterator/incrementable_traits.h>
#include <__iterator/iter_move.h>
#include <__iterator/iter_swap.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/next.h>
#include <__iterator/prev.h>
#include <__iterator/readable_traits.h>
#include <__type_traits/enable_if.h>
#include <__type_traits/is_reference.h>
#include <__type_traits/is_same.h>
#include <__type_traits/remove_cvref.h>
#include <__utility/declval.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#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 _AlgPolicy>
struct _IterOps;
#if _LIBCPP_STD_VER >= 20
struct _RangeAlgPolicy {};
template <>
struct _IterOps<_RangeAlgPolicy> {
template <class _Iter>
using __value_type = iter_value_t<_Iter>;
template <class _Iter>
using __iterator_category = ranges::__iterator_concept<_Iter>;
template <class _Iter>
using __difference_type = iter_difference_t<_Iter>;
static constexpr auto advance = ranges::advance;
static constexpr auto distance = ranges::distance;
static constexpr auto __iter_move = ranges::iter_move;
static constexpr auto iter_swap = ranges::iter_swap;
static constexpr auto next = ranges::next;
static constexpr auto prev = ranges::prev;
static constexpr auto __advance_to = ranges::advance;
};
#endif
struct _ClassicAlgPolicy {};
template <>
struct _IterOps<_ClassicAlgPolicy> {
template <class _Iter>
using __value_type = typename iterator_traits<_Iter>::value_type;
template <class _Iter>
using __iterator_category = typename iterator_traits<_Iter>::iterator_category;
template <class _Iter>
using __difference_type = typename iterator_traits<_Iter>::difference_type;
// advance
template <class _Iter, class _Distance>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static void advance(_Iter& __iter, _Distance __count) {
std::advance(__iter, __count);
}
// distance
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static typename iterator_traits<_Iter>::difference_type
distance(_Iter __first, _Iter __last) {
return std::distance(__first, __last);
}
template <class _Iter>
using __deref_t = decltype(*std::declval<_Iter&>());
template <class _Iter>
using __move_t = decltype(std::move(*std::declval<_Iter&>()));
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static void __validate_iter_reference() {
static_assert(
is_same<__deref_t<_Iter>, typename iterator_traits<__remove_cvref_t<_Iter> >::reference>::value,
"It looks like your iterator's `iterator_traits<It>::reference` does not match the return type of "
"dereferencing the iterator, i.e., calling `*it`. This is undefined behavior according to [input.iterators] "
"and can lead to dangling reference issues at runtime, so we are flagging this.");
}
// iter_move
template <class _Iter, __enable_if_t<is_reference<__deref_t<_Iter> >::value, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static
// If the result of dereferencing `_Iter` is a reference type, deduce the result of calling `std::move` on it.
// Note that the C++03 mode doesn't support `decltype(auto)` as the return type.
__move_t<_Iter>
__iter_move(_Iter&& __i) {
__validate_iter_reference<_Iter>();
return std::move(*std::forward<_Iter>(__i));
}
template <class _Iter, __enable_if_t<!is_reference<__deref_t<_Iter> >::value, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static
// If the result of dereferencing `_Iter` is a value type, deduce the return value of this function to also be a
// value -- otherwise, after `operator*` returns a temporary, this function would return a dangling reference to
// that temporary. Note that the C++03 mode doesn't support `auto` as the return type.
__deref_t<_Iter>
__iter_move(_Iter&& __i) {
__validate_iter_reference<_Iter>();
return *std::forward<_Iter>(__i);
}
// iter_swap
template <class _Iter1, class _Iter2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static void iter_swap(_Iter1&& __a, _Iter2&& __b) {
std::iter_swap(std::forward<_Iter1>(__a), std::forward<_Iter2>(__b));
}
// next
template <class _Iterator>
_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 _Iterator next(_Iterator, _Iterator __last) {
return __last;
}
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 __remove_cvref_t<_Iter>
next(_Iter&& __it, typename iterator_traits<__remove_cvref_t<_Iter> >::difference_type __n = 1) {
return std::next(std::forward<_Iter>(__it), __n);
}
// prev
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 __remove_cvref_t<_Iter>
prev(_Iter&& __iter, typename iterator_traits<__remove_cvref_t<_Iter> >::difference_type __n = 1) {
return std::prev(std::forward<_Iter>(__iter), __n);
}
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX14 void __advance_to(_Iter& __first, _Iter __last) {
__first = __last;
}
// advance with sentinel, a la std::ranges::advance
template <class _Iter>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static __difference_type<_Iter>
__advance_to(_Iter& __iter, __difference_type<_Iter> __count, const _Iter& __sentinel) {
return _IterOps::__advance_to(__iter, __count, __sentinel, typename iterator_traits<_Iter>::iterator_category());
}
private:
// advance with sentinel, a la std::ranges::advance -- InputIterator specialization
template <class _InputIter>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static __difference_type<_InputIter> __advance_to(
_InputIter& __iter, __difference_type<_InputIter> __count, const _InputIter& __sentinel, input_iterator_tag) {
__difference_type<_InputIter> __dist = 0;
for (; __dist < __count && __iter != __sentinel; ++__dist)
++__iter;
return __count - __dist;
}
// advance with sentinel, a la std::ranges::advance -- BidirectionalIterator specialization
template <class _BiDirIter>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static __difference_type<_BiDirIter>
__advance_to(_BiDirIter& __iter,
__difference_type<_BiDirIter> __count,
const _BiDirIter& __sentinel,
bidirectional_iterator_tag) {
__difference_type<_BiDirIter> __dist = 0;
if (__count >= 0)
for (; __dist < __count && __iter != __sentinel; ++__dist)
++__iter;
else
for (__count = -__count; __dist < __count && __iter != __sentinel; ++__dist)
--__iter;
return __count - __dist;
}
// advance with sentinel, a la std::ranges::advance -- RandomIterator specialization
template <class _RandIter>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static __difference_type<_RandIter>
__advance_to(_RandIter& __iter,
__difference_type<_RandIter> __count,
const _RandIter& __sentinel,
random_access_iterator_tag) {
auto __dist = _IterOps::distance(__iter, __sentinel);
_LIBCPP_ASSERT_VALID_INPUT_RANGE(
__count == 0 || (__dist < 0) == (__count < 0), "__sentinel must precede __iter when __count < 0");
if (__count < 0)
__dist = __dist > __count ? __dist : __count;
else
__dist = __dist < __count ? __dist : __count;
__iter += __dist;
return __count - __dist;
}
};
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___ALGORITHM_ITERATOR_OPERATIONS_H
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