is_unsigned template in C++

The std::is_unsigned template of C++ STL is used to check whether the type is a unsigned arithmetic type or not. It returns a boolean value showing the same.

Syntax:

template <class T > struct is_unsigned;

Parameters: This template contains single parameter T (Trait class) to check whether T is a unsigned arithmetic type or not.

Return Value:This template returns a boolean value as shown below:

• True: if the type is a un-signed arithmetic type.
• False: if the type is a signed arithmetic type.

Below programs illustrate the std::is_unsigned template in C++ STL:

Program 1:

// C++ program to illustrate
// std::is_unsigned template

#include <iostream>
#include <type_traits>
using namespace std;

class gfg {
};

enum sam : unsigned {};
enum class raj : unsigned {};

int main()
{
    cout << boolalpha;
    cout << "is_unsigned:" << '\n';
    cout << "unsigned int:"
         << is_unsigned<unsigned int>::value << '\n';
    cout << "gfg:"
         << is_unsigned<gfg>::value << '\n';
    cout << "sam:"
         << is_unsigned<sam>::value << '\n';
    cout << "raj:"
         << is_unsigned<raj>::value << '\n';

    return 0;
}

Output:

is_unsigned:
unsigned int:true
gfg:false
sam:false
raj:false

Program 2:

// C++ program to illustrate
// std::is_unsigned template

#include <iostream>
#include <type_traits>
using namespace std;

int main()
{
    cout << boolalpha;
    cout << "is_unsigned:" << '\n';
    cout << "signed char:"
         << is_unsigned<signed char>::value << '\n';
    cout << "unsigned char:"
         << is_unsigned<unsigned char>::value << '\n';
    cout << "signed int:"
         << is_unsigned<signed int>::value << '\n';

    return 0;
}

Output:

is_unsigned:
signed char:false
unsigned char:true
signed int:false

Program 3:

// C++ program to illustrate
// std::is_unsigned template

#include <iostream>
#include <type_traits>
using namespace std;

int main()
{
    cout << boolalpha;
    cout << "is_unsigned:" << '\n';
    cout << "bool:"
         << is_unsigned<bool>::value << '\n';
    cout << "float:"
         << is_unsigned<float>::value << '\n';
    cout << "double:"
         << is_unsigned<double>::value << '\n';

    return 0;
}

Output:

is_unsigned:
bool:true
float:false
double:false