std::is_enum
From cppreference.com
Defined in header <type_traits> | ||
template<class T > struct is_enum; | (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.
If the program adds specializations for std::is_enum or std::is_enum_v, the behavior is undefined.
Contents |
[edit]Template parameters
| T | - | a type to check |
[edit]Helper variable template
template<class T > constexprbool 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> |
[edit]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); enumclass Ec :int{}; static_assert(std::is_enum_v<Ec>==true); static_assert(std::is_enum_v<int>==false); int main(){}
[edit]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) |
