is_final template in C++14

The std::is_final template of C++ STL is used to check whether the type is a final or not.

Syntax:

template < class T > struct is_final;

Parameter: This template contains single parameter T (Trait class) to check whether T is a final type.

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

• True: if the type is a final.
• False: if the type is a non-final.

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

Note: Please select C++14 in the online IDE to run the code.

Program 1:

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

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

// main program

class gfg {
};

class sam final {
}; // using class

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

    return 0;
}

Output:

is_final:
gfg:false
sam:true
int:false

Program 2:

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

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

// main program
struct gfg {
};

struct sam final {
}; // using struct

int main()
{
    cout << boolalpha;
    cout << "is_final:"
         << '\n';
    cout << "gfg:"
         << is_final<gfg>::value
         << '\n';
    cout << "sam:"
         << is_final<sam>::value
         << '\n';
    cout << "float:"
         << is_final<float>::value
         << '\n';

    return 0;
}

Output:

is_final:
gfg:false
sam:true
float:false

Program 3:

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

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

// main program

// using union
union sam final {
};

union gfg {
};

int main()
{
    cout << boolalpha;
    cout << "is_final:"
         << '\n';
    cout << "sam:"
         << is_final<sam>::value
         << '\n';
    cout << "gfg:"
         << is_final<gfg>::value
         << '\n';
    cout << "char:"
         << is_final<char>::value
         << '\n';

    return 0;
}

Output:

is_final:
sam:true
gfg:false
char:false