mysql::sets::Is_metric_set_traits Concept Reference

True if Test is a "metric" Set traits class, i.e., it is bounded, and it is possible to compute differences between boundaries. More...

#include <set_traits.h>

Concept definition

template<class Test>
concept mysql::sets::Is_metric_set_traits = 
    Is_bounded_set_traits<Test> &&
    std::same_as<typename Test::Difference_t, typename Test::Difference_t> &&
    (!std::same_as<typename Test::Difference_t, void>) &&
    requires(Test t, typename Test::Element_t v1, typename Test::Element_t v2,
             typename Test::Difference_t d1, typename Test::Difference_t d2) {
      { Test::sub(v1, v2) } -> std::same_as<typename Test::Difference_t>;
      { Test::add(v1, d1) } -> std::same_as<typename Test::Element_t>;
      { Test::add(d1, v1) } -> std::same_as<typename Test::Element_t>;
      { Test::add(d1, d2) } -> std::same_as<typename Test::Difference_t>;
    }

Detailed Description

True if Test is a "metric" Set traits class, i.e., it is bounded, and it is possible to compute differences between boundaries.

This requires that it has a member type Difference_t (which may or may not be equal to Element_t), that the difference between two Element_t values is of type Difference_t and can be computed using member function sub, that two Difference_t objects can be added using add to give another Difference_t, and that a Difference_t can be added to a Element_t using add to give another Element_t.