7 Concepts library [concepts.lib]

7.5 Object concepts [concepts.lib.object]

7.5.4 Concept Regular [concepts.lib.object.regular]

template <class T> concept bool Regular = Semiregular<T> && EqualityComparable<T>;

Note: The Regular concept is satisfied by types that behave similarly to built-in types like int and that are comparable with ==. — end note ]