operator==, <=>(std::indirect)

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std::indirect

成员函数

indirect::indirect

indirect::~indirect

indirect::operator=

观察器

indirect::operator->indirect::operator*

indirect::valueless_after_move

indirect::get_allocator

修改器

indirect::swap

非成员函数

operator==operator<=>

swap(std::indirect)

推导指引

辅助类

hash<std::indirect>

 

<tbody> </tbody>

在标头 <memory> 定义
比较两个 indirect 对象
template< class U, class A > constexpr bool operator==( const indirect& lhs, const indirect<U, A>& rhs ) noexcept(noexcept(*lhs == *rhs));	(1)	(C++26 起)
template< class U, class A > constexpr /*synth-three-way-result*/<T, U> operator<=>( const indirect& lhs, const indirect<U, A>& rhs );	(2)	(C++26 起)
比较一个 indirect 对象与一个值
template< class U > constexpr bool operator==( const indirect& ind, const U& value ) noexcept(noexcept(*lhs == value));	(3)	(C++26 起)
template< class U > constexpr /*synth-three-way-result*/<T, U> operator<=>( const indirect& ind, const U& value );	(4)	(C++26 起)

进行 indirect 对象上的比较。

/*synth-three-way-result*/ 的定义见 synth-three-way-result。

1,2) 比较两个 indirect 对象，比较结果定义如下：

运算符	lhs 无值		lhs 有值
	rhs 无值	rhs 有值	rhs 无值	rhs 有值
operator==	true	false	false	*lhs == *rhs
operator<=>	!lhs.valueless_after_move() <=> !rhs.valueless_after_move()			synth-three-way     (*lhs, *rhs)

1) 如果表达式 *lhs == *rhs 非良构或它的结果不可转换到 bool，那么程序非良构。

3,4) 比较一个 indirect 对象与一个值，比较结果定义如下：

运算符	ind 无值	ind 有值
operator==	false	*ind == value
operator<=>	std::strong_ordering::less	synth-three-way (*ind, value)

3) 如果表达式 *ind == value 非良构或它的结果不可转换到 bool，那么程序非良构。

参数

lhs, rhs, ind	-	要比较的 indirect 对象
value	-	与拥有的值比较的值

返回值

如上所述。

示例