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std::is_enum
Defined in header <type_traits> |
||
---|---|---|
|
(since C++11) |
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
.
The behavior of a program that adds specializations for std::is_enum
or std::is_enum_v
is undefined.
Template parameters
T | - | a type to check |
Helper variable template
|
(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 <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
(C++11)
|
checks if a type is an integral type (class template) |
(C++11)
|
checks if a type is an arithmetic type (class template) |
(C++11)
|
checks if a type is a scalar type (class template) |
(C++23)
|
checks if a type is a scoped enumeration type (class template) |
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