# partial_ordering Class

class Qt::partial_orderingQt::partial_ordering represents the result of a comparison that allows for unordered results. More...

Header: | #include <QtCompare> |

CMake: | find_package(Qt6 REQUIRED COMPONENTS Core) target_link_libraries(mytarget PRIVATE Qt6::Core) |

qmake: | QT += core |

Since: | Qt 6.7 |

## Public Functions

partial_ordering(std::partial_ordering stdorder) | |

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

## Static Public Members

const Qt::partial_ordering | equivalent |

const Qt::partial_ordering | greater |

const Qt::partial_ordering | less |

const Qt::partial_ordering | unordered |

## Related Non-Members

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) |

## Detailed Description

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:

- 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*.

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 }

Comparing Qt::partial_ordering::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]`

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

Constructs a Qt::partial_ordering 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 partial_ordering::operator std::partial_ordering() const

Converts this Qt::partial_ordering 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 Qt::partial_ordering partial_ordering::equivalent

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

### const Qt::partial_ordering partial_ordering::greater

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

### const Qt::partial_ordering partial_ordering::less

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

### const Qt::partial_ordering partial_ordering::unordered

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

## Related Non-Members

`[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*)

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`

.

`[constexpr noexcept]`

bool operator!=(Qt::partial_ordering *lhs*, Qt::partial_ordering *rhs*)

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

`[constexpr noexcept]`

bool operator==(Qt::partial_ordering *lhs*, Qt::partial_ordering *rhs*)

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

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