std::Relation (3) - Linux Manuals
std::Relation: std::Relation
NAME
Synopsis
Defined in header <concepts>
template <class R, class T, class U>
concept Relation = (1) (since C++20)
std::Predicate<R, T, T> && std::Predicate<R, U, U> &&
std::Predicate<R, T, U> && std::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.