From Get docs
Cpp/docs/latest/types/is abstract


Defined in header <type_traits>
template< class T >
struct is_abstract;
(since C++11)

If T is an abstract class (that is, a non-union class that declares or inherits at least one pure virtual function), provides the member constant value equal true. For any other type, value is false.

If T is a non-union class type, T shall be a complete type; otherwise, the behavior is undefined.

Template parameters

T - a type to check

Helper variable template

template< class T >
inline constexpr bool is_abstract_v = is_abstract<T>::value;
(since C++17)

Inherited from std::integral_constant

Member constants



true if T is an abstract class 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>


#include <iostream>
#include <type_traits>
struct A {
    int m;
struct B {
    virtual void foo();
struct C {
    virtual void foo() = 0;
struct D : C {};
int main()
    std::cout << std::boolalpha;
    std::cout << std::is_abstract<A>::value << '\n';
    std::cout << std::is_abstract<B>::value << '\n';
    std::cout << std::is_abstract<C>::value << '\n';
    std::cout << std::is_abstract<D>::value << '\n';



See also


checks if a type is a non-union class type

(class template)


checks if a type is a polymorphic class type

(class template)

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