std::iter_swap(std::reverse_iterator)

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

技术规范

符号索引

外部库

 

迭代器库

迭代器概念
indirectly_readable (C++20) indirectly_writable (C++20) weakly_incrementable (C++20) incrementable (C++20) input_or_output_iterator (C++20) sentinel_for (C++20) sized_sentinel_for (C++20)	input_iterator (C++20) 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
iterator_traits input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (C++20) iterator (C++17 中弃用)	incrementable_traits (C++20) indirectly_readable_traits (C++20) iter_value_titer_difference_titer_reference_titer_rvalue_reference_titer_common_reference_t (C++20)(C++20)(C++20)(C++20)(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)
工具
indirect_result_t	projected
迭代器适配器
reverse_iterator move_iterator (C++11) 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) back_insert_iterator front_insert_iterator insert_iterator	make_reverse_iterator (C++14) make_move_iterator (C++11) default_sentinel_tdefault_sentinel (C++20)(C++20) unreachable_sentinel_tunreachable_sentinel (C++20)(C++20) make_const_iterator (C++23) make_const_sentinel (C++23) back_inserter front_inserter inserter
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) endcend (C++11)(C++14) sizessize (C++17)(C++20)	rbegincrbegin (C++14)(C++14) rendcrend (C++14)(C++14) 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)

 

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)

交换二个调整的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);

此函数模板对通常无限定或有限定查找不可见，而只能在 std::reverse_iterator<Iter> 为参数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);
 
    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)