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std::is_enum(3) | C++ Standard Libary | std::is_enum(3) |
NAME¶
std::is_enum - std::is_enum
Synopsis¶
Defined in header <type_traits>
template< class T > (since C++11)
struct is_enum;
std::is_enum is a UnaryTypeTrait.
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.
If the program adds specializations for std::is_enum or std::is_enum_v, the
behavior
is undefined.
Template parameters¶
T - a type to check
Helper variable template
template< class T > (since C++17)
inline constexpr bool is_enum_v = is_enum<T>::value;
Inherited from std::integral_constant
Member constants¶
value true if T is an enumeration type, false otherwise
[static] (public static member constant)
Member functions¶
operator bool converts the object to bool, returns value
(public member function)
operator() returns value
(C++14) (public member function)
Member types¶
Type Definition
value_type bool
type std::integral_constant<bool, value>
Example¶
// Run this code
#include <type_traits>
struct A { enum E {}; };
static_assert(std::is_enum_v<A> == false);
static_assert(std::is_enum_v<A::E> == true);
enum E {};
static_assert(std::is_enum_v<E> == true);
enum class Ec : int {};
static_assert(std::is_enum_v<Ec> == true);
static_assert(std::is_enum_v<int> == false);
int main() {}
See also¶
is_integral checks if a type is an integral type
(C++11) (class template)
is_arithmetic checks if a type is an arithmetic type
(C++11) (class template)
is_scalar checks if a type is a scalar type
(C++11) (class template)
is_scoped_enum checks if a type is a scoped enumeration type
(C++23) (class template)
2024.06.10 | http://cppreference.com |