Namespaces
Variants
Views
Actions

std::is_polymorphic

From cppreference.com
< cpp‎ | types
 
 
 
Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
C numeric limits interface
Runtime type information
Type traits
Primary type categories
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
Type properties
(C++11)
(C++11)
(C++11)
is_polymorphic
(C++11)
(C++14)
Supported operations
Relationships and property queries
(C++11)
(C++11)
(C++11)
(C++11)
Type modifications
(C++11)(C++11)(C++11)
Type transformations
(C++11)
(C++11)
(C++11)
Type trait constants
 
Defined in header <type_traits>
template< class T >
struct is_polymorphic;
(since C++11)

If T is a polymorphic class (that is, a non-union class that declares or inherits at least one 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 a polymorphic class type , false otherwise
(public static member constant)

Member functions

operator bool
converts the object to bool, returns value
(public member function)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>

[edit] Example

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

Output:

false
true
true

[edit] See also

(C++11)
checks if a type is a class type (but not union type)
(class template) [edit]
checks if a type is abstract class type
(class template) [edit]