std::partial_order

template< class T >
constexpr std::partial_ordering partial_order(const T& a, const T& b);

Compares two values using 3-way comparison and produces a result of type std::partial_ordering.

Specifically,

• If the expression a <=> b is well-formed and its result is convertible to std::partial_ordering, returns that result.
• Otherwise, if the expression a <=> b is well-formed, but its result is not convertible to std::partial_ordering, then the function is defined as deleted.
• Otherwise, if the expression a <=> b is ill-formed, but the expressions a == b and a < b are both well-formed and convertible to bool,
• if a == b is true, returns std::partial_ordering::equivalent
• otherwise, if a < b is true, returns std::partial_ordering::less
• otherwise, returns std::partial_ordering::greater
• Otherwise, the function is defined as deleted.

Parameters

Return value

A value of type std::partial_ordering, as described above.

Notes

Example

See also