Can I call a virtual destructor using a function pointer?

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Category:Languages

I have class Data which can hold a pointer to an object. I want to be able to call its destructor manually later on, for which I need its address stored in a variable but it seems that taking the address of constructor/destructor is forbidden. Is there any way around this ?

struct Data {    union {     long i;     float f;     void* data_ptr;   } _data;    std::type_index _typeIndex;   void (*_destructor_ptr)();    template<typename T>   void Init() {   if constexpr (std::is_integral<T>::value) {     //   }   else if constexpr (std::is_floating_point<T>::value) {     //   }   else {     _data.data_ptr = new T;     _typeIndex = std::type_index(typeid(T));     _destructor_ptr = &T::~T; // << -- can't do this   } } 

 


Store a lambda, suitably converted:

void (*_destructor_ptr)(void *v);  // ...  _destructor_ptr = +[](void* v) { delete static_cast<T*>(v); }; 

Note that you must pass _data.data_ptr for v. If you intend to store a plain function pointer, the lambda may not capture or implicitly refer to _data.data_ptr.

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