In rust that will return itself, which allows you to chain method calls, if that's your style. For example, with the Timer class [1], you could write:

  someTimer.set_interval(1000).start();

instead of writing:

  someTimer.set_interval(1000);
  someTimer.start();

[1]: https://github.com/cybergeek94/kiss-ui/blob/master/src/timer...