is_signed Class
The latest version of this topic can be found at is_signed Class.
Test if type is signed integer.
Syntax
template <class Ty>
struct is_signed;
Parameters
Ty
The type to query.
Remarks
An instance of the type predicate holds true if the type Ty is a signed integral type or a cv-qualified signed integral type, otherwise it holds false.
Example
// std_tr1__type_traits__is_signed.cpp
// compile with: /EHsc
#include <type_traits>
#include <iostream>
struct trivial
{
int val;
};
int main()
{
std::cout << "is_signed<trivial> == " << std::boolalpha
<< std::is_signed<trivial>::value << std::endl;
std::cout << "is_signed<int> == " << std::boolalpha
<< std::is_signed<int>::value << std::endl;
std::cout << "is_signed<unsigned int> == " << std::boolalpha
<< std::is_signed<unsigned int>::value << std::endl;
std::cout << "is_signed<float> == " << std::boolalpha
<< std::is_signed<float>::value << std::endl;
return (0);
}
is_signed<trivial> == false
is_signed<int> == true
is_signed<unsigned int> == false
is_signed<float> == false
Requirements
Header: <type_traits>
Namespace: std