std::has_virtual_destructor
From cppreference.com
| Defined in header <type_traits>
|
||
| template< class T > struct has_virtual_destructor; |
(since C++11) | |
If T is a type with a virtual destructor, 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.
Helper variable template
| template< class T > inline constexpr bool has_virtual_destructor_v = has_virtual_destructor<T>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
true if T has a virtual destructor , 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> |
Notes
If a class has a public virtual destructor, it can be derived from, and the derived object can be safely deleted through a pointer to the base object (GotW #18)
Example
Run this code
#include <iostream> #include <type_traits> #include <string> #include <stdexcept> int main() { std::cout << std::boolalpha << "std::string has a virtual destructor? " << std::has_virtual_destructor<std::string>::value << '\n' << "std::runtime_error has a virtual destructor? " << std::has_virtual_destructor<std::runtime_error>::value << '\n'; }
Output:
std::string has a virtual destructor? false std::runtime_error has a virtual destructor? true
See also
| (C++11)(C++11)(C++11) |
checks if a type has a non-deleted destructor (class template) |