- Qt 6.6
- Qt Core
- C++ Classes
- QPartialOrdering
- Qt 6.6.1 Reference Documentation

# QPartialOrdering Class

QPartialOrdering represents the result of a comparison that allows for unordered results. More...

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

- List of all members, including inherited members

## Static Public Members

const QPartialOrdering | Equivalent
const QPartialOrdering | Greater
const QPartialOrdering | Less
const QPartialOrdering | Unordered

## Related Non-Members

bool | operator!=(QPartialOrdering lhs, QPartialOrdering rhs)
bool | operator==(QPartialOrdering lhs, QPartialOrdering rhs)

## Detailed Description

A value of type QPartialOrdering is typically returned from a three-way comparison function. Such a function compares two objects, and it may either establish that the two objects are ordered relative to each other, or that they are not ordered. The QPartialOrdering value returned from the comparison function represents one of those possibilities.

The possible values of type QPartialOrdering are, in fact, fully represented by the following four static values:

- `QPartialOrdering::Less` represents that the first object is less than the second;
- `QPartialOrdering::Equivalent` represents that the first object is equivalent to the second;
- `QPartialOrdering::Greater` represents that the first object is greater than the second;
- `QPartialOrdering::Unordered` represents that the first object is not ordered with respect to the second.

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
     }

A QPartialOrdering value which represents an unordered result will always return false when compared against literal 0.

## Member Variable Documentation

### const QPartialOrdering QPartialOrdering::Equivalent

Represents the result of a comparison where the value on the left hand side is equivalent to the value on the right hand side.

### const QPartialOrdering QPartialOrdering::Greater

Represents the result of a comparison where the value on the left hand side is greater than the value on the right hand side.

### const QPartialOrdering QPartialOrdering::Less

Represents the result of a comparison where the value on the left hand side is less than the value on the right hand side.

### const QPartialOrdering QPartialOrdering::Unordered

Represents the result of a comparison where the value on the left hand side is not ordered with respect to the value on the right hand side.

## Related Non-Members

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

Return true if lhs and rhs represent different results; otherwise, returns true.

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

Return true if lhs and rhs represent the same result; otherwise, returns false.