std::iter_move(std::reverse_iterator)

 

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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)
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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)
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istream_iterator ostream_iterator	istreambuf_iterator ostreambuf_iterator
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ranges::iter_move (C++20)
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advance distance prev (C++11) next (C++11)	ranges::advance (C++20) ranges::distance (C++20) ranges::prev (C++20) ranges::next (C++20)
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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)

 

friend constexpr std::iter_rvalue_reference_t<Iter>     iter_move( const std::reverse_iterator& i ) noexcept(/* see below */);		(C++20 起)

转型解引用调节后的底层迭代器的结果到其关联的右值引用类型。

函数体等价于：

auto tmp = i.base();
return std::ranges::iter_move(--tmp);

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

i

-

源逆向迭代器。

返回值

右值引用或纯右值临时量。

复杂度

常数。

异常

noexcept 说明：  

noexcept(

  std::is_nothrow_copy_constructible_v<Iter> &&
  noexcept(std::ranges::iter_move(--std::declval<Iter&>()))

)

示例

运行此代码

#include <iomanip>
#include <iostream>
#include <iterator>
#include <string>
#include <vector>
 
void print(auto const& rem, auto const& v) {
    for (std::cout << rem << "[" << size(v) << "] { "; auto const& s : v)
        std::cout << quoted(s) << " ";
    std::cout << "}\n";
}
 
int main()
{
    std::vector<std::string> p { "Alpha", "Bravo", "Charlie" }, q;
 
    print("p", p), print("q", q);
 
    using RI = std::reverse_iterator<std::vector<std::string>::iterator>;
 
    for (RI iter{ p.rbegin() }, rend{ p.rend() }; iter != rend; ++iter) {
        q.emplace_back( /* ADL */ iter_move(iter) );
    }
 
    print("p", p), print("q", q);
}

可能的输出：

p[3] { "Alpha" "Bravo" "Charlie" }
q[0] { }
p[3] { "" "" "" }
q[3] { "Charlie" "Bravo" "Alpha" }

参阅

iter_move (C++20)	将解引用迭代器的结果转型为其关联的右值引用类型 (定制点对象)
iter_move (C++20)	转型解引用底层迭代器的结果为其所关联的右值引用类型 (函数)
move (C++11)	获得右值引用 (函数模板)
move_if_noexcept (C++11)	若移动构造函数不抛出则获得右值引用 (函数模板)
forward (C++11)	转发一个函数实参 (函数模板)
ranges::move (C++20)	将某一范围的元素移动到一个新的位置 (niebloid)
ranges::move_backword (C++20)	按从后往前的顺序移动某一范围的元素到新的位置 (niebloid)