let foo_cons = @int(0);
let foo_dest = @int(0);

class foo {
  foo() { 
    foo_cons = foo_cons + 1;
  }
  foo(foo f) {
    foo_cons = foo_cons + 1;
  }
  ~foo() {
    foo_dest = foo_dest + 1;
  }
};
fun operator=(foo! x, foo y)-> foo! { return x; }
model DefaultConstructible<foo> { };
model Regular<foo> { };

struct bar<T> where { DefaultConstructible<T>, Regular<T> }
{
  T f;
  int y;
};

fun yow() -> int@ {
  let b = @bar<foo> { f = @foo(), y = 3 };
  return b.y;
}

fun main() -> int@ {
  let y = yow();
  return y - 3 + foo_cons - foo_dest;
}