Qt::partial_ordering 表示允许用于无序结果的比较结果。 更多...
头: | #include <QtCompare> |
CMake: |
find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core) |
qmake: | QT += core |
Since: | Qt 6.7 |
partial_ordering (std::partial_ordering stdorder ) | |
std::partial_ordering | operator std::partial_ordering () const |
const Qt::partial_ordering | equivalent |
const Qt::partial_ordering | greater |
const Qt::partial_ordering | less |
const Qt::partial_ordering | unordered |
bool | is_eq (Qt::partial_ordering o ) |
bool | is_gt (Qt::partial_ordering o ) |
bool | is_gteq (Qt::partial_ordering o ) |
bool | is_lt (Qt::partial_ordering o ) |
bool | is_lteq (Qt::partial_ordering o ) |
bool | is_neq (Qt::partial_ordering o ) |
bool | operator!= (Qt::partial_ordering lhs , Qt::partial_ordering rhs ) |
bool | operator== (Qt::partial_ordering lhs , Qt::partial_ordering rhs ) |
A value of type Qt::partial_ordering 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.
Qt::partial_ordering has four values, represented by the following symbolic constants:
Qt::partial_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::partial_ordering compare(T lhs, T rhs); // defined out-of-line ~~~ Qt::partial_ordering 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
Qt::partial_ordering::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 .
[constexpr noexcept]
partial_ordering::
partial_ordering
(
std::partial_ordering
stdorder
)
构造 Qt::partial_ordering 对象从 stdorder 使用下列规则:
[constexpr noexcept]
std::partial_ordering
partial_ordering::
operator std::partial_ordering
() const
转换此 Qt::partial_ordering value to a std::partial_ordering object using the following rules:
Represents the result of a comparison where the two operands are equivalent.
Represents the result of a comparison where the left operand is greater than the right operand.
Represents the result of a comparison where the left operand is less than the right operand.
Represents the result of a comparison where there is no ordering relationship between the two operands.
[constexpr noexcept]
bool
is_eq
(
Qt::partial_ordering
o
)
[constexpr noexcept]
bool
is_gt
(
Qt::partial_ordering
o
)
[constexpr noexcept]
bool
is_gteq
(
Qt::partial_ordering
o
)
[constexpr noexcept]
bool
is_lt
(
Qt::partial_ordering
o
)
[constexpr noexcept]
bool
is_lteq
(
Qt::partial_ordering
o
)
[constexpr noexcept]
bool
is_neq
(
Qt::partial_ordering
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
.
[constexpr noexcept]
bool
operator!=
(
Qt::partial_ordering
lhs
,
Qt::partial_ordering
rhs
)
返回 True 若 lhs and rhs represent different results; otherwise, returns true.
[constexpr noexcept]
bool
operator==
(
Qt::partial_ordering
lhs
,
Qt::partial_ordering
rhs
)
返回 True 若 lhs and rhs represent the same result; otherwise, returns false.