std::signed_integral

Since C++20

Header: <concepts>

The concept signed_integral is satisfied if and only if T is an integral type and std::is_signed_v is true.

# Declarations

template< class T >
concept signed_integral = std::integral<T> && std::is_signed_v<T>;

(since C++20)

# Notes

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

# Example

#include <concepts>
#include <iostream>
#include <string_view>
 
void test(std::signed_integral auto x, std::string_view text = "")
{
    std::cout << text << " (" + (text == "") << x << ") is a signed integral\n";
}
 
void test(std::unsigned_integral auto x, std::string_view text = "")
{
    std::cout << text << " (" + (text == "") << x << ") is an unsigned integral\n";
}
 
void test(auto x, std::string_view text = "")
{
    std::cout << text << " (" + (text == "") << x << ") is non-integral\n";
}
 
int main()
{
    test(42);               // signed
    test(0xFULL, "0xFULL"); // unsigned
    test('A');              // platform-dependent
    test(true, "true");     // unsigned
    test(4e-2, "4e-2");     // non-integral (hex-float)
    test("∫∫");             // non-integral
}

# See also