template< class T >
struct has_virtual_destructor;
std::has_virtual_destructor is a UnaryTypeTrait.
If T is a type with a virtual destructor, the base characteristic is std::true_type. For any other type, the base characteristic is std::false_type.
If T is an incomplete non-union class type, the behavior is undefined.
If the program adds specializations for std::has_virtual_destructor or std::has_virtual_destructor_v, the behavior is undefined.
template< class T >
constexpr bool has_virtual_destructor_v = has_virtual_destructor<T>::value;
T has a virtual destructor, false otherwise
If a class C 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). In this case, std::is_polymorphic<C>::value is true.
#include <type_traits>
struct S {};
static_assert(!std::has_virtual_destructor_v<S>);
struct B { virtual ~B() {} };
static_assert(std::has_virtual_destructor_v<B>);
struct D : B { ~D() {} };
static_assert(std::has_virtual_destructor_v<D>);
int main()
{
B* pd = new D;
delete pd;
}[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR Applied to Behavior as published Correct behavior LWG 2015 C++11 the behavior was undefined ifT is an incomplete union type the base characteristic is
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