28     static unsigned dtor_called;  member in X
32     ~X() {++dtor_called;}  in ~X()
37 unsigned X::dtor_called = 0;  member in X
43     static unsigned dtor_called;  member in Y
46     ~Y() {++dtor_called;}  in ~Y()
52 unsigned Y::dtor_called = 0;  member in Y
172         assert(X::dtor_called == 0);  in main()
181         X::dtor_called = 0;  in main()
183         assert(X::dtor_called == 1);  in main()
195         X::dtor_called = 0;  in main()
197         assert(X::dtor_called == 1);  in main()
210         X::dtor_called = 0;  in main()
212         assert(X::dtor_called == 1);  // from inside std::swap  in main()
227         assert(Y::dtor_called == 0);  in main()
236         Y::dtor_called = 0;  in main()
238         assert(Y::dtor_called == 1);  in main()
250         Y::dtor_called = 0;  in main()
252         assert(Y::dtor_called == 1);  in main()
265         Y::dtor_called = 0;  in main()
267         assert(Y::dtor_called == 0);  in main()