The std::is_enum template of C++ STL is used to check whether the given type is enum or not. It returns a boolean value showing the same.
Syntax:
template <class T> struct is_enum;
Parameter: This template accepts single parameter T (Trait class) to check whether T is a enumeration type or not.
Return Value: This template returns a boolean value as shown below:
- True: if the type is a enumeration.
- False: if the type is a non-enumeration.
Below programs illustrate the std::is_enum template in C++:
Program 1::
// C++ program to illustrate // is_enum template #include <iostream> #include <type_traits> using namespace std;
class GFG1 {
}; enum class GFG2 { var1,
var2,
var3,
var4
}; // Driver code int main()
{ cout << boolalpha;
cout << "is_enum:" << endl;
cout << "GFG1: "
<< is_enum<GFG1>::value << endl;
cout << "GFG2: "
<< is_enum<GFG2>::value << endl;
return 0;
} |
Output:
is_enum: GFG1: false GFG2: true
Program 2::
// C++ program to illustrate // is_enum template #include <iostream> #include <type_traits> using namespace std;
class GFG1 {
}; enum class GFG2 : int {};
// Driver code int main()
{ cout << boolalpha;
cout << "is_enum:" << endl;
cout << "GFG1: "
<< is_enum<GFG1>::value << '\n' ;
cout << "GFG2: "
<< is_enum<GFG2>::value << '\n' ;
cout << "int: "
<< is_enum< int >::value << '\n' ;
return 0;
} |
Output:
is_enum: GFG1: false GFG2: true int: false