-- Storing an OWNED class value into a container is a MOVE (iteration 16's
-- route-table pattern found the disclosed "move-on-push" double-free: the
-- container's drop plan frees elements, so the pusher must not also drop
-- what it pushed). Texts stay copy-stored — the mixed push below pins both.
interface Handler {
  fn handle(x: Int) -> Int
}

class AddOne {
  n: Int
  fn handle(x: Int) -> Int { return x + self.n }
}

class Route {
  path: Text
  h: Handler
}

class App {
  routes: multi Route
  names: multi Text

  fn add(take r: Route, name: Text) {
    push(self.routes, r);
    push(self.names, name);
  }

  fn run(path: Text, x: Int) -> Int {
    for r in self.routes {
      if r.path == path { return r.h.handle(x); }
    }
    return -1;
  }
}

fn main(args: multi Text) -> Int {
  let app = App { routes: [], names: [] };
  app.add(Route { path: "/a", h: AddOne { n: 7 } }, "a");
  app.add(Route { path: "/b", h: AddOne { n: 100 } }, "b");
  print_int(app.run("/b", 1));
  print_int(app.run("/a", 1));
  print_int(app.run("/x", 1));
  print_int(count(app.names));
  return 0;
}