test when c++ destructor is called
// order_of_destruction.cpp
#include <cstdio>
struct A1 { virtual ~A1() { printf("A1 dtor\n"); } };
struct A2 : A1 { virtual ~A2() { printf("A2 dtor\n"); } };
struct A3 : A2 { virtual ~A3() { printf("A3 dtor\n"); } };
struct B1 { ~B1() { printf("B1 dtor\n"); } };
struct B2 : B1 { ~B2() { printf("B2 dtor\n"); } };
struct B3 : B2 { ~B3() { printf("B3 dtor\n"); } };
int main() {
A1 * a = new A3;
delete a;
printf("\n");
B1 * b = new B3;
delete b;
printf("\n");
B3 * b2 = new B3;
delete b2;
}
Output: A3 dtor
A2 dtor
A1 dtor
B1 dtor
B3 dtor
B2 dtor
B1 dtor