Re: Interaction of delete and destructor

I use the code below to study delete and destructor.

#include <iostream>
using namespace std;

struct A {
 virtual ~A() { cout << "~A()" << endl; }; //LINE1

 void operator delete(void* p) {
   cout << "A::operator delete" << endl;
   free(p);
 }
};

struct B : A {
 void operator delete(void* p) {
   cout << "B::operator delete" << endl; //LINE2
   free(p);
 }
 ~B(){ cout << "~B()" << endl; }; //LINE3
};

int main() {
 A* ap ;
 B *bp = new B;
 ap = bp;
 delete ap; //LINE4
}

The output of the code is:
~B()
~A()
B::operator delete

I can not understand the output. When LINE4 is executed, LINE1 is
executed, right?
Since ~A() is virtual, LINE3 is called. How can LINE2 be executed?
"delete ap" calls A's destructor. Then B's destructor is called. Can
B's destructor call B's operator delete?