How to delete object constructed via placement new operator?

Question

char * buf = new char[sizeof(T)];
new (buf) T;
T * t = (T *)buf;
//code...
//here I should destruct *t but as it is argument of template and can be
//instantiated vi         


        

Answer 1

Call the destructor

T * t = (T *)buf;
t->~T();

then free memory with delete[] buf. Calling destructors explicitly is exactly how it is done for objects created with placement new.