std::reverse_iterator<Iter>::operator*,->

 

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)
工具
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)

 

	(1)
reference operator*() const;			(C++17 前)
constexpr reference operator*() const;			(C++17 起)
		(2)
pointer operator->() const;				(C++17 前)
constexpr pointer operator->() const;				(C++17 起) (C++20 前)
constexpr pointer operator->() const     requires (std::is_pointer_v<Iter> ||               requires (const Iter i) { i.operator->(); });				(C++20 起)

返回指向 current 前一元素的引用或指针。

1) 等价于 Iter tmp = current; return *--tmp;。

2) 等价于 return std::addressof(operator*());。	(C++20 前)
2) 若 Iter 为指针类型则等价于 return current - 1;。否则等价于 return std::prev(current).operator->();。	(C++20 起)

参数

（无）

返回值

指向 current 前一元素的引用或指针。

示例

运行此代码

#include <complex>
#include <iostream>
#include <iterator>
#include <vector>
 
int main()
{
    using RI0 = std::reverse_iterator<int*>;
    int a[]{0, 1, 2, 3};
    RI0 r0{std::rbegin(a)};
    std::cout << "*r0 = " << *r0 << '\n';
    *r0 = 42;
    std::cout << "a[3] = " << a[3] << '\n';
 
    using RI1 = std::reverse_iterator<std::vector<int>::iterator>;
    std::vector<int> vi{0, 1, 2, 3};
    RI1 r1{vi.rend() - 2};
    std::cout << "*r1 = " << *r1 << '\n';
 
    using RI2 = std::reverse_iterator<std::vector<std::complex<double>>::iterator>;
    std::vector<std::complex<double>> vc{{1,2}, {3,4}, {5,6}, {7,8}};
    RI2 r2{vc.rbegin() + 1};
    std::cout << "vc[2] = (" << r2->real() << ',' << r2->imag() << ")\n";
}

输出：

*r0 = 3
a[3] = 42
*r1 = 1
vc[2] = (5,6)

参阅

operator[]

按索引访问元素 (公开成员函数)