QPartialOrdering 类

QPartialOrdering 表示允许用于无序结果的比较结果。 更多...

头：	#include <QPartialOrdering>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Core) target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake:	QT += core
Since:	Qt 6.0

• 所有成员列表，包括继承成员

公共函数

	QPartialOrdering (std::partial_ordering stdorder )
std::partial_ordering	operator std::partial_ordering () const

静态公共成员

const QPartialOrdering	Equivalent
const QPartialOrdering	Greater
const QPartialOrdering	Less
const QPartialOrdering	Unordered
const QPartialOrdering	equivalent
const QPartialOrdering	greater
const QPartialOrdering	less
const QPartialOrdering	unordered

相关非成员

(从 6.7 起) bool	is_eq (QPartialOrdering o )
(从 6.7 起) bool	is_gt (QPartialOrdering o )
(从 6.7 起) bool	is_gteq (QPartialOrdering o )
(从 6.7 起) bool	is_lt (QPartialOrdering o )
(从 6.7 起) bool	is_lteq (QPartialOrdering o )
(从 6.7 起) bool	is_neq (QPartialOrdering o )
bool	operator!= (QPartialOrdering lhs , QPartialOrdering rhs )
bool	operator== (QPartialOrdering lhs , QPartialOrdering rhs )

详细描述

A value of type QPartialOrdering is typically returned from a three-way comparison function. Such a function compares two objects, establishing whether they are ordered and, if so, their ordering. It uses this return type to indicate that the ordering is partial; that is, not all pairs of values are ordered.

QPartialOrdering has four values, represented by the following symbolic constants:

• less represents that the left operand is less than the right;
• equivalent represents that the two operands are equivalent;
• greater represents that the left operand is greater than the right;
• unordered represents that the two operands are not ordered .

QPartialOrdering 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:
QPartialOrdering compare(T lhs, T rhs); // defined out-of-line
~~~
QPartialOrdering result = compare(a, b);
if (result < 0) {
    // a is less than b
}
if (compare(c, d) >= 0) {
    // c is greater than or equal to d
}
					

比较 QPartialOrdering::unordered against literal 0 always returns a false 结果。

另请参阅 Qt::strong_ordering , Qt::weak_ordering ，和 比较类型概述 .

成员函数文档编制

[constexpr noexcept] QPartialOrdering:: QPartialOrdering ( std::partial_ordering stdorder )

Constructs a QPartialOrdering object from stdorder 使用下列规则：

• std::partial_ordering::less converts to less .
• std::partial_ordering::equivalent converts to equivalent .
• std::partial_ordering::greater converts to greater .
• std::partial_ordering::unordered converts to unordered

[constexpr noexcept] std::partial_ordering QPartialOrdering:: operator std::partial_ordering () const

转换此 QPartialOrdering value to a std::partial_ordering object using the following rules:

• less converts to std::partial_ordering::less.
• equivalent converts to std::partial_ordering::equivalent.
• greater converts to std::partial_ordering::greater.
• unordered converts to std::partial_ordering::unordered.

成员变量文档编制

const QPartialOrdering QPartialOrdering:: Equivalent

Represents the result of a comparison where the two operands are equivalent.

const QPartialOrdering QPartialOrdering:: Greater

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

const QPartialOrdering QPartialOrdering:: Less

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

const QPartialOrdering QPartialOrdering:: Unordered

Represents the result of a comparison where there is no ordering relationship between the two operands.

const QPartialOrdering QPartialOrdering:: equivalent

Represents the result of a comparison where the two operands are equivalent.

const QPartialOrdering QPartialOrdering:: greater

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

const QPartialOrdering QPartialOrdering:: less

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

const QPartialOrdering QPartialOrdering:: unordered

Represents the result of a comparison where there is no ordering relationship between the two operands.

相关非成员

[constexpr noexcept, since 6.7] bool is_eq ( QPartialOrdering o )

[constexpr noexcept, since 6.7] bool is_gt ( QPartialOrdering o )

[constexpr noexcept, since 6.7] bool is_gteq ( QPartialOrdering o )

[constexpr noexcept, since 6.7] bool is_lt ( QPartialOrdering o )

[constexpr noexcept, since 6.7] bool is_lteq ( QPartialOrdering o )

[constexpr noexcept, since 6.7] bool is_neq ( QPartialOrdering o )

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

函数	Operation
is_eq	o == 0
is_neq	o != 0
is_lt	o < 0
is_lteq	o <= 0
is_gt	o > 0
is_gteq	o >= 0

These functions are provided for compatibility with std::partial_ordering .

该函数在 Qt 6.7 引入。

[constexpr noexcept] bool operator!= ( QPartialOrdering lhs , QPartialOrdering rhs )

返回 True 若 lhs and rhs represent different results; otherwise, returns true.

[constexpr noexcept] bool operator== ( QPartialOrdering lhs , QPartialOrdering rhs )

返回 True 若 lhs and rhs represent the same result; otherwise, returns false.

内容

• 公共函数

• 静态公共成员

• 相关非成员

• 详细描述