QPartialOrdering Class▲
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Header: QPartialOrdering
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Since: Qt 6.0
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CMake:
find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core)
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qmake: QT += core
Detailed Description▲
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:
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less represents that the left operand is less than the right;
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equivalent represents that the two operands are equivalent;
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greater represents that the left operand is greater than the right;
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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
}Comparing QPartialOrdering::unordered against literal 0 always returns a false result.
See Also▲
Member Function Documentation▲
[default] QPartialOrdering::QPartialOrdering(int stdorder)▲
Constructs a QPartialOrdering object from stdorder using the following rules:
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std::partial_ordering::less converts to less.
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std::partial_ordering::equivalent converts to equivalent.
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std::partial_ordering::greater converts to greater.
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std::partial_ordering::unordered converts to unordered
Member Variable Documentation▲
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.
Related Non-Members▲
[constexpr, since 6.7] bool is_eq(QPartialOrdering o)▲
[constexpr, since 6.7] bool is_gt(QPartialOrdering o)
[constexpr, since 6.7] bool is_gteq(QPartialOrdering o)
[constexpr, since 6.7] bool is_lt(QPartialOrdering o)
[constexpr, since 6.7] bool is_lteq(QPartialOrdering o)
[constexpr, since 6.7] bool is_neq(QPartialOrdering o)
Converts o into the result of one of the six relational operators:
|
Function |
Operation |
|---|---|
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is_eq |
o == 0 |
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is_neq |
o != 0 |
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is_lt |
o < 0 |
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is_lteq |
o <= 0 |
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is_gt |
o > 0 |
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is_gteq |
o >= 0 |
These functions are provided for compatibility with std::partial_ordering.
This function was introduced in Qt 6.7.
[constexpr] bool operator!=(QPartialOrdering lhs, QPartialOrdering rhs)▲
Return true if lhs and rhs represent different results; otherwise, returns true.
[constexpr] bool operator==(QPartialOrdering lhs, QPartialOrdering rhs)▲
Return true if lhs and rhs represent the same result; otherwise, returns false.