weak_ordering Class

class Qt ::weak_ordering

Qt::weak_ordering represents a comparison where equivalent values are still distinguishable. 更多...

頭：	#include <QtCompare>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Core) target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake:	QT += core
Since:	Qt 6.7

• 所有成員列錶，包括繼承成員

公共函數

	weak_ordering (std::weak_ordering stdorder )
Qt::partial_ordering	operator Qt::partial_ordering () const
std::weak_ordering	operator std::weak_ordering () const

靜態公共成員

const Qt::weak_ordering	equivalent
const Qt::weak_ordering	greater
const Qt::weak_ordering	less

相關非成員

bool	is_eq (Qt::weak_ordering o )
bool	is_gt (Qt::weak_ordering o )
bool	is_gteq (Qt::weak_ordering o )
bool	is_lt (Qt::weak_ordering o )
bool	is_lteq (Qt::weak_ordering o )
bool	is_neq (Qt::weak_ordering o )
bool	operator!= (Qt::weak_ordering lhs , Qt::weak_ordering rhs )
bool	operator== (Qt::weak_ordering lhs , Qt::weak_ordering rhs )

詳細描述

A value of type Qt::weak_ordering is typically returned from a three-way comparison function. Such a function compares two objects and establishes how they are ordered. It uses this return type to indicate that the ordering is weak; that is, equivalent values may be distinguishable.

Qt::weak_ordering has three values, represented by the following symbolic constants:

• less 錶示左操作數 < 右操作數；
• equivalent represents that the left operand is equivalent to the right;
• greater represents that the left operand is greater than the right,

Qt::weak_ordering is idiomatically used by comparing an instance against a literal zero, for instance like this:

// given a, b, c, d as objects of some type that allows for a 3-way compare,
// and a compare function declared as follows:
Qt::weak_ordering compare(T lhs, T rhs); // defined out-of-line
~~~
Qt::weak_ordering result = compare(a, b);
if (result < 0) {
    // a is less than b
}
if (compare(c, d) >= 0) {
    // c is greater than or equivalent to d
}
					

另請參閱 Qt::strong_ordering , Qt::partial_ordering ，和 比較類型概述 .

成員函數文檔編製

[constexpr noexcept] weak_ordering:: weak_ordering ( std::weak_ordering stdorder )

構造 Qt::weak_ordering 對象從 stdorder 使用下列規則：

• std::weak_ordering::less converts to less .
• std::weak_ordering::equivalent converts to equivalent .
• std::weak_ordering::greater converts to greater .

[constexpr noexcept] Qt::partial_ordering weak_ordering:: operator Qt::partial_ordering () const

轉換此 Qt::weak_ordering value to a Qt::partial_ordering object using the following rules:

• less converts to Qt::partial_ordering::less .
• equivalent converts to Qt::partial_ordering::equivalent .
• greater converts to Qt::partial_ordering::greater .

[constexpr noexcept] std::weak_ordering weak_ordering:: operator std::weak_ordering () const

轉換此 Qt::weak_ordering value to a std::weak_ordering object using the following rules:

• less converts to std::weak_ordering::less.
• equivalent converts to std::weak_ordering::equivalent.
• greater converts to std::weak_ordering::greater.

成員變量文檔編製

const Qt::weak_ordering weak_ordering:: equivalent

Represents the result of a comparison where the left operand is equivalent to the right operand.

const Qt::weak_ordering weak_ordering:: greater

Represents the result of a comparison where the left operand is greater than the right operand.

const Qt::weak_ordering weak_ordering:: less

Represents the result of a comparison where the left operand is less than the right operand.

相關非成員

[constexpr noexcept] bool is_eq ( Qt::weak_ordering o )

[constexpr noexcept] bool is_gt ( Qt::weak_ordering o )

[constexpr noexcept] bool is_gteq ( Qt::weak_ordering o )

[constexpr noexcept] bool is_lt ( Qt::weak_ordering o )

[constexpr noexcept] bool is_lteq ( Qt::weak_ordering o )

[constexpr noexcept] bool is_neq ( Qt::weak_ordering o )

轉換 o into the result of one of the six relational operators:

函數	操作
is_eq	o == 0
is_neq	o != 0
is_lt	o < 0
is_lteq	o <= 0
is_gt	o > 0
is_gteq	o >= 0

提供這些函數是為兼容 std::weak_ordering .

[constexpr noexcept] bool operator!= ( Qt::weak_ordering lhs , Qt::weak_ordering rhs )

返迴 True 若 lhs and rhs 錶示不同結果；否則，返迴 true。

[constexpr noexcept] bool operator== ( Qt::weak_ordering lhs , Qt::weak_ordering rhs )

返迴 True 若 lhs and rhs 錶示相同結果；否則，返迴 false。

內容

1. 公共函數

2. 靜態公共成員

3. 相關非成員

4. 詳細描述