operator==,!=,<,<=,>,>=,<=>(std::move_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)

诊断库

内存管理库

元编程库(C++11)

通用工具库

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迭代器库

范围库(C++20)

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执行控制库(C++26)

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) 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 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::move_iterator

成员函数

move_iterator::move_iterator

move_iterator::operator=

move_iterator::base

move_iterator::operator*move_iterator::operator->

move_iterator::operator[]

move_iterator::operator++move_iterator::operator+move_iterator::operator+=move_iterator::operator--move_iterator::operator-move_iterator::operator-=

非成员函数

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

operator==(move_sentinel) (C++20)

operator+

operator-

operator-(move_sentinel) (C++20)

iter_move (C++20)

iter_swap (C++20)

make_move_iterator (C++11)

 

在标头 <iterator> 定义
template<class Iter1, class Iter2 > bool operator==(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(1)	(C++17 起为 constexpr)
template<class Iter1, class Iter2 > bool operator!=(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(2)	(C++17 起为 constexpr) (C++20 前)
template<class Iter1, class Iter2 > bool operator<(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(3)	(C++17 起为 constexpr)
template<class Iter1, class Iter2 > bool operator<=(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(4)	(C++17 起为 constexpr)
template<class Iter1, class Iter2 > bool operator>(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(5)	(C++17 起为 constexpr)
template<class Iter1, class Iter2 > bool operator>=(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(6)	(C++17 起为 constexpr)
template<class Iter1, std::three_way_comparable_with<Iter1> Iter2 > constexprstd::compare_three_way_result_t<Iter1, Iter2>     operator<=>(conststd::move_iterator<Iter1>& lhs,                  conststd::move_iterator<Iter2>& rhs );	(7)	(C++20 起)

比较 lhs 与 rhs 的底层迭代器。

1) 此重载只有在 lhs.base()== rhs.base() 良构并且可转换到 bool 时才会参与重载决议。 3-6) 此重载只有在 lhs.base()< rhs.base() 良构并且可转换到 bool 时才会参与重载决议。 != 运算符从 operator== 运算符合成。

(C++20 起)

参数

lhs, rhs

-

要比较的迭代器适配器

返回值

1)lhs.base()== rhs.base()

2)lhs.base()!= rhs.base()

3)lhs.base()> rhs.base()

4)lhs.base()>= rhs.base()

5)lhs.base()< rhs.base()

6)lhs.base()<= rhs.base()

7)rhs.base()<=> lhs.base()

示例

运行此代码

#include <cassert>#include <iterator>   int main(){int a[]{9, 8, 7, 6};// │ └───── x, y// └──────── z   // “x” 与 “y” 相等，但 “x” 大于 “z”std::move_iterator<int*> x{std::end(a)-1}, y{std::end(a)-1}, z{std::end(a)-2};   // 双路比较assert( x == y );assert(!(x != y));assert(!(x < y));assert( x <= y );assert(!(x == z));assert( x != z );assert(!(x < z));assert(!(x <= z));   // 三路比较assert( x <=> y ==0);assert(!(x <=> y <0));assert(!(x <=> y >0));assert(!(x <=> z ==0));assert(!(x <=> z <0));assert( x <=> z >0);}

参阅

operator==(std::move_sentinel) (C++20)

比较底层迭代器与底层哨位 (函数模板)