| Defined in header <type_traits> | ||
|---|---|---|
template< class T > struct is_enum; | (since C++11) |
Checks whether T is an enumeration type. Provides the member constant value which is equal to true, if T is an enumeration type . Otherwise, value is equal to false.
Template parameters
| T | - | a type to check |
Helper variable template
template< class T > constexpr bool is_enum_v = is_enum<T>::value; | (since C++17) |
Inherited from std::integral_constant
Member constants
| value [static] | true if T is an enumeration type , false otherwise (public static member constant) |
Member functions
| operator bool | converts the object to bool, returns value (public member function) |
| operator() (C++14) | returns value (public member function) |
Member types
| Type | Definition |
|---|---|
value_type | bool |
type | std::integral_constant<bool, value> |
Example
#include <iostream>
#include <type_traits>
class A {};
enum E {};
enum class Ec : int {};
int main()
{
std::cout << std::boolalpha;
std::cout << std::is_enum<A>::value << '\n';
std::cout << std::is_enum<E>::value << '\n';
std::cout << std::is_enum<Ec>::value << '\n';
std::cout << std::is_enum<int>::value << '\n';
}Output:
false true true false
See also
| (C++11) | checks if a type is void (class template) |
| (C++11) | checks if a type is a pointer type (class template) |
| (C++11) | checks if a type is arithmetic type (class template) |
| std::experimental::is_enum_v
(library fundamentals TS) | variable template alias of std::is_enum::value (variable template) |
Please login to continue.