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

T - 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

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)
returns value
(public member function)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>


Feature-test macro Value Std Comment
__cpp_lib_is_scoped_enum 202011L (C++23) std::is_scoped_enum

Possible implementation

template<typename E>
struct is_scoped_enum : std::bool_constant<requires
    requires std::is_enum_v<E>;
    requires !std::is_convertible_v<E, std::underlying_type_t<E>>;


#include <type_traits>
class A {};
enum E {};
enum struct Es { oz };
enum class Ec : int {};
int main()
    static_assert(std::is_scoped_enum_v<A> == false);
    static_assert(std::is_scoped_enum_v<E> == false);
    static_assert(std::is_scoped_enum_v<Es> == true);
    static_assert(std::is_scoped_enum_v<Ec> == true);
    static_assert(std::is_scoped_enum_v<int> == false);

See also

checks if a type is an integral type
(class template)
checks if a type is an arithmetic type
(class template)
checks if a type is a scalar type
(class template)
checks if a type is an enumeration type
(class template)

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