weak_ordering Class | Qt Core 6.7.3 (original) (raw)
class Qt::weak_ordering
Qt::weak_ordering represents a comparison where equivalent values are still distinguishable. More...
| Header: | #include |
|---|---|
| CMake: | find_package(Qt6 REQUIRED COMPONENTS Core) target_link_libraries(mytarget PRIVATE Qt6::Core) |
| qmake: | QT += core |
| Since: | Qt 6.7 |
Public Functions
Static Public Members
| bool | is_eq(Qt::weak_ordering o) |
|---|---|
| bool | is_gt(Qt::weak_ordering o) |
| bool | is_gteq(Qt::weak_ordering o) |
| bool | is_lt(Qt::weak_ordering o) |
| bool | is_lteq(Qt::weak_ordering o) |
| bool | is_neq(Qt::weak_ordering o) |
| bool | operator!=(Qt::weak_ordering lhs, Qt::weak_ordering rhs) |
| bool | operator==(Qt::weak_ordering lhs, Qt::weak_ordering rhs) |
Detailed Description
A value of type Qt::weak_ordering is typically returned from a three-way comparison function. Such a function compares two objects and establishes how they are ordered. It uses this return type to indicate that the ordering is weak; that is, equivalent values may be distinguishable.
Qt::weak_ordering has three values, represented by the following symbolic constants:
- less represents that the left operand is less than the right;
- equivalent represents that the left operand is equivalent to the right;
- greater represents that the left operand is greater than the right,
Qt::weak_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::weak_ordering compare(T lhs, T rhs); // defined out-of-line
~~~
Qt::weak_ordering result = compare(a, b); if (result < 0) { // a is less than b }
if (compare(c, d) >= 0) { // c is greater than or equivalent to d }
See also Qt::strong_ordering, Qt::partial_ordering, and Comparison types overview.
Member Variable Documentation
const Qt::weak_ordering weak_ordering::equivalent
Represents the result of a comparison where the left operand is equivalent to the right operand.
const Qt::weak_ordering weak_ordering::greater
Represents the result of a comparison where the left operand is greater than the right operand.
const Qt::weak_ordering weak_ordering::less
Represents the result of a comparison where the left operand is less than the right operand.
Related Non-Members
[constexpr noexcept] bool is_eq(Qt::weak_ordering o)
[constexpr noexcept] bool is_gt(Qt::weak_ordering o)
[constexpr noexcept] bool is_gteq(Qt::weak_ordering o)
[constexpr noexcept] bool is_lt(Qt::weak_ordering o)
[constexpr noexcept] bool is_lteq(Qt::weak_ordering o)
[constexpr noexcept] bool is_neq(Qt::weak_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::weak_ordering.
[constexpr noexcept] bool operator!=(Qt::weak_ordering lhs, Qt::weak_ordering rhs)
Return true if lhs and rhs represent different results; otherwise, returns true.
[constexpr noexcept] bool operator==(Qt::weak_ordering lhs, Qt::weak_ordering rhs)
Return true if lhs and rhs represent the same result; otherwise, returns false.
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