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