std::experimental::ranges::Relation (3) - Linux Manuals

std::experimental::ranges::Relation: std::experimental::ranges::Relation


std::experimental::ranges::Relation - std::experimental::ranges::Relation


Defined in header <experimental/ranges/concepts>
template <class R, class T, class U>
concept bool Relation =
Predicate<R, T, T> &&
Predicate<R, U, U> &&
const std::remove_reference_t<T>&,
const std::remove_reference_t<U>&> &&
Predicate<R, (1) (ranges TS)
const std::remove_reference_t<T>&,
const std::remove_reference_t<U>&>,
const std::remove_reference_t<T>&,
const std::remove_reference_t<U>&>> &&
Predicate<R, T, U> &&
Predicate<R, U, T>;

The concept Relation<R, T, U> specifies that R defines a binary relation over the set of expressions whose type and value category are those encoded by either T or U.

* r, an expression such that decltype((r)) is R,
* t, an expression such that decltype((t)) is T,
* u, an expression such that decltype((u)) is U,

and let C be ranges::common_reference_t<const std::remove_reference_t<T>&, const std::remove_reference_t<U>&>,
then Relation<R, T, U> is satisfied only if

* bool(r(t, u)) == bool(r(C(t), C(u))) and
* bool(r(u, t)) == bool(r(C(u), C(t))).