std::is_scoped_enum

< cpp‎ | types

Defined in header `<type_traits>`
template< class T > struct is_scoped_enum;		(since C++23)

Checks whether T is a scoped enumeration type. Provides the member constant value which is equal to true, if T is a scoped enumeration type. Otherwise, value is equal to false.

The behavior of a program that adds specializations for is_scoped_enum or is_scoped_enum_v is undefined.

Template parameters

a type to check

Helper variable template

template< class T > inline constexpr bool is_scoped_enum_v = is_scoped_enum<T>::value;		(since C++23)

Inherited from std::integral_constant

Member constants

value

[static]

true if T is a scoped 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 struct Es { oz };
 
enum class Ec : int {};
 
int main() 
{
    std::cout << std::boolalpha;
    std::cout << std::is_scoped_enum_v<A> << '\n';
    std::cout << std::is_scoped_enum_v<E> << '\n';
    std::cout << std::is_scoped_enum_v<Es> << '\n';
    std::cout << std::is_scoped_enum_v<Ec> << '\n';
    std::cout << std::is_scoped_enum_v<int> << '\n';
}

Output:

false
false
true
true
false

is_integral (C++11)	checks if a type is an integral type (class template)
is_arithmetic (C++11)	checks if a type is an arithmetic type (class template)
is_scalar (C++11)	checks if a type is a scalar type (class template)
is_enum (C++11)	checks if a type is an enumeration type (class template)