app.window_rect().x.step_by(50) fails as iterator

[npetrangelo]

I am trying to draw a row of ellipses and this for loop will not compile, complaining that the returned pub struct Range<S = scalar::Default> does not satisfy the Iterator trait bound, even though to my understanding, Iterator is supposed to be implemented for all Ranges.

for i in app.window_rect().x.step_by(50) {
    draw.ellipse()
        .color(RED)
        .x_y(i as f32, -100.0);
}

The rest of my project can be found here.

[npetrangelo]

I'm not sure there's really an issue with this library or Rust itself, but it is very unclear what the idiomatic way is to loop over this range with a custom step.

[npetrangelo]

I found a solution, although I wish I could directly cast a Range to a Range.

let w = app.window_rect().w() as i32;
for i in (-w..w).step_by(100) {
    draw.ellipse()
        .color(RED)
        .x_y(i as f32 - 200.0, -100.0);
}