7 Concepts library [concepts.lib]

7.3 Core language concepts [concepts.lib.corelang]

7.3.2 Concept Same [concepts.lib.corelang.same]

template <class T, class U> concept bool Same = is_same<T, U>::value; // see below

1

There need not be any subsumption relationship between Same<T, U> and is_same<T, U>::value.

2

Remarks: For the purposes of constraint checking, Same<T, U> implies Same<U, T>.