Type traits which are true for all const/volatile/signed/unsigned version of a fundamental type

Question

Consider the following tests:

std::is_same<T, bool>::value
std::is_same<T, char>::value
std::is_same<T, short int>::value
std::is_same<T, int>::value
std::is_same<T, long int>::value
std::is_same<T, long long int>::value
std::is_same<T, float>::value
std::is_same<T, double>::value
std::is_same<T, long double>::value

The problem is if T = const unsigned char, all tests will be false, and I would like this one std::is_same<T, char>::value to be true. Or if T = volatile signed long long int I would like std::is_same<T, long long int>::value to be true. How to do that with type_traits ?

Answer 1

Use std::remove_cv to remove const and volatile if present:

std::is_same<std::remove_cv<T>::type, long long int>::value;

Answer 2

You can use std::remove_cv to take care of the const-volatile specifiers.

And you can use std::make_signed to take care of the signed/unsigned issue. Although, I don't particularly like that idea (is unsigned char really the same as char? No.).

std::is_same< std::make_signed< std::remove_cv<T> >, char >::value;

Will be true for any of char, unsigned char, const char, const unsigned char, and the volatile versions of those.