std::is_abstract
From cppreference.com
Defined in header
<type_traits>
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||
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.
Contents |
Inherited from std::integral_constant
Member constants
value
[static]
|
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) |
operator()
(C++14)
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returns value (public member function) |
Member types
Type | Definition |
value_type
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bool
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type
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std::integral_constant<bool, value> |
[edit] Example
Run this code
#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'; }
Output:
false false true true
[edit] See also
(C++11)
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checks if a type is a class type (but not union type) (class template) |
(C++11)
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checks if a type is polymorphic class type (class template) |
(library fundamentals TS)
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variable template alias of std::is_abstract::value (variable template) |