std::signed_integral(3)

NAME
std::signed_integral - std::signed_integral

Synopsis
   Defined in header <concepts>
   template < class T > (since C++20)
   concept signed_integral = std::integral<T> && std::is_signed_v<T>;
   The concept signed_integral<T> is satisfied if and only if T is an integral type and
   std::is_signed_v<T> is true.

Notes
   signed_integral<T> may be satisfied by a type that is not a signed integer type, for
   example, char (on a system where char is signed).

Example
// Run this code
 #include <concepts>
 #include <iostream>
 void print(std::signed_integral auto i) {
     std::cout << "Signed integral: " << i << '\n';
 }
 void print(std::unsigned_integral auto u) {
     std::cout << "Unsigned integral: " << u << '\n';
 }
 void print(auto x) {
     std::cout << "Non-integral: " << x << '\n';
 }
 int main() {
     print(42); // signed
     print(0xFull); // unsigned
     print(true); // unsigned
     print('A'); // platform-dependent
     print(4e-2); // non-integral (hex-float)
     print("∫∫∫"); // non-integral
 }

Possible output:
 Signed integral: 42
 Unsigned integral: 15
 Unsigned integral: 1
 Signed integral: A
 Non-integral: 0.04
 Non-integral: ∫∫∫

See also
   is_integral checks if a type is an integral type
   (C++11) (class template)
   is_signed checks if a type is a signed arithmetic type
   (C++11) (class template)