# 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 |

## Public Functions

QPartialOrdering(std::partial_ordering stdorder) | |

std::partial_ordering | operator std::partial_ordering() const |

## Static Public Members

const QPartialOrdering | Equivalent |

const QPartialOrdering | Greater |

const QPartialOrdering | Less |

const QPartialOrdering | Unordered |

const QPartialOrdering | equivalent |

const QPartialOrdering | greater |

const QPartialOrdering | less |

const QPartialOrdering | unordered |

## Related Non-Members

`(since 6.7)` bool | is_eq(QPartialOrdering o) |

`(since 6.7)` bool | is_gt(QPartialOrdering o) |

`(since 6.7)` bool | is_gteq(QPartialOrdering o) |

`(since 6.7)` bool | is_lt(QPartialOrdering o) |

`(since 6.7)` bool | is_lteq(QPartialOrdering o) |

`(since 6.7)` bool | is_neq(QPartialOrdering o) |

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, 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 }

Comparing QPartialOrdering::unordered against literal 0 always returns a `false`

result.

**See also **Qt::strong_ordering, Qt::weak_ordering, and Comparison types overview.

## Member Function Documentation

`[constexpr noexcept]`

QPartialOrdering::QPartialOrdering(std::partial_ordering *stdorder*)

Constructs a QPartialOrdering object from *stdorder* using the following rules:

- 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

Converts this 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.

## 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 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*)

Converts *o* into the result of one of the six relational operators:

Function | 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`

.

This function was introduced in Qt 6.7.

`[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.

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