7 Concepts library [concepts.lib]

7.3 Core language concepts [concepts.lib.corelang]

7.3.8 Concept SignedIntegral [concepts.lib.corelang.signedintegral]

template <class T> concept bool SignedIntegral = Integral<T> && is_signed<T>::value; // see below

1

There need not be any subsumption relationship between SignedIntegral<T> and is_signed<T>::value.

2

[ Note: SignedIntegral<T> may be satisfied even for types that are not signed integral types ( ISO/IEC 14882:2014 §[basic.fundamental]); for example, char.  — end note ]