std::iter_swap(std::reverse_iterator)

 

C++

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功能特性测试宏 (C++20)

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迭代器库

迭代器概念
indirectly_readable (C++20) indirectly_writable (C++20) weakly_incrementable (C++20) incrementable (C++20) is-integer-like is-signed-integer-like (C++20)(C++20)	sentinel_for (C++20) sized_sentinel_for (C++20) input_iterator (C++20) output_iterator (C++20) input_or_output_iterator (C++20)	forward_iterator (C++20) bidirectional_iterator (C++20) random_access_iterator (C++20) contiguous_iterator (C++20)
迭代器原语
input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (C++20)	iter_value_titer_difference_titer_reference_titer_const_reference_titer_rvalue_reference_titer_common_reference_t (C++20)(C++20)(C++20)(C++23)(C++20)(C++20)	iterator (C++17 中弃用) iterator_traits incrementable_traits (C++20) indirectly_readable_traits (C++20)
算法概念与工具
间接可调用概念
indirectly_unary_invocableindirectly_regular_unary_invocable (C++20)(C++20)	indirect_unary_predicate (C++20) indirect_binary_predicate (C++20)	indirect_equivalence_relation (C++20) indirect_strict_weak_order (C++20)
常用算法要求
indirectly_movable (C++20) indirectly_movable_storable (C++20) indirectly_copyable (C++20)	indirectly_copyable_storable (C++20)   indirectly_swappable (C++20) indirectly_comparable (C++20)	permutable (C++20) mergeable (C++20) sortable (C++20)
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indirect_result_t (C++20)	projected (C++20)	projected_value_t (C++26)
迭代器适配器
reverse_iterator make_reverse_iterator (C++14) move_iterator (C++11) make_move_iterator (C++11) default_sentinel_tdefault_sentinel (C++20)(C++20) unreachable_sentinel_tunreachable_sentinel (C++20)(C++20)	front_insert_iterator back_insert_iterator inserter insert_iterator front_inserter back_inserter move_sentinel (C++20)	common_iterator (C++20) counted_iterator (C++20) basic_const_iterator (C++23) const_iterator (C++23) const_sentinel (C++23) make_const_iterator (C++23) make_const_sentinel (C++23)
流迭代器 istream_iterator    ostream_iterator istreambuf_iterator ostreambuf_iterator	迭代器定制点 ranges::iter_move (C++20) ranges::iter_swap (C++20)
迭代器操作 advance distance prev (C++11)   next (C++11) ranges::advance (C++20) ranges::distance (C++20) ranges::prev (C++20) ranges::next (C++20)	范围访问 begincbegin (C++11)(C++14) rbegincrbegin (C++14)(C++14)   endcend (C++11)(C++14) rendcrend (C++14)(C++14)   sizessize (C++17)(C++20) empty (C++17) data (C++17)

 

std::reverse_iterator

成员函数

reverse_iterator::reverse_iterator

reverse_iterator::operator=

reverse_iterator::base

reverse_iterator::operator*reverse_iterator::operator->

reverse_iterator::operator[]

reverse_iterator::operator++reverse_iterator::operator+reverse_iterator::operator+=reverse_iterator::operator--reverse_iterator::operator-reverse_iterator::operator-=

非成员函数

operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20)

operator+

operator-

iter_move (C++20)

iter_swap (C++20)

make_reverse_iterator (C++14)

 

template< std::indirectly_swappable<Iter> Iter2 >     friend constexpr void         iter_swap( const reverse_iterator& x,                    const std::reverse_iterator<Iter2>& y ) noexcept(/*see below*/);		(C++20 起)

交换两个调整后的底层迭代器所指向的元素。函数体等价于：

auto tmp_x = x.base();
auto tmp_y = y.base();
ranges::iter_swap(--tmp_x, --tmp_y);

此函数模板对常规的无限定或有限定查找不可见，而只能在 std::reverse_iterator<Iter> 为实参的关联类时由实参依赖查找找到。

参数

x, y

-

要交换元素的逆向迭代器

返回值

（无）

复杂度

常数。

异常

noexcept 说明：  

noexcept(

    std::is_nothrow_copy_constructible_v<Iter> &&
    std::is_nothrow_copy_constructible_v<Iter2> &&
    noexcept(ranges::iter_swap(--std::declval<Iter&>(), --std::declval<Iter2&>()))

)

示例

运行此代码

#include <iostream>
#include <iterator>
#include <list>
#include <vector>
 
int main()
{
    std::vector v{1, 2, 3};
    std::list l{4, 5, 6};
 
    std::reverse_iterator<std::vector<int>::iterator> r1{v.rbegin()};
    std::reverse_iterator<std::list<int>::iterator> r2{l.rbegin()};
 
    std::cout << *r1 << ' ' << *r2 << '\n';
 
    iter_swap(r1, r2); // ADL
 
    std::cout << *r1 << ' ' << *r2 << '\n';
}

输出：

3 6
6 3

参阅

swap	交换两个对象的值 (函数模板)
swap_ranges	交换两个范围的元素 (函数模板)
iter_swap	交换两个迭代器所指向的元素 (函数模板)
iter_swap (C++20)	交换两个可解引用对象所引用的值 (定制点对象)
iter_swap (C++20)	交换两个底层迭代器所指向的对象 (函数模板)