Reasoning for WindowBuilder methods taking '&mut self' while CanvasBuilder methods take 'mut self'?

[BeefaloKing]

I'm quite new to Rust, so maybe there's something going on I don't understand, but it seems awkward that the window and canvas builders behave differently.

Relevant snippets: https://github.com/Rust-SDL2/rust-sdl2/blob/fe411c6b8765d53654b24886524ee2f3d94892b2/src/sdl2/render.rs#L741-L744 https://github.com/Rust-SDL2/rust-sdl2/blob/fe411c6b8765d53654b24886524ee2f3d94892b2/src/sdl2/video.rs#L1145-L1149

If you set your configuration and build all at once, then you don't notice the difference.

let window = video.window(name, width, height)
    .position_centered()
    /* etc. */
    .build()
    .unwrap();

let canvas = window.into_canvas()
    .present_vsync()
    /* etc. */
    .build()
    .unwrap();

However, if for some reason you wanted to split things into discrete steps (say to allow for different options to be selected at runtime based on a user provided config), then they no longer behave the same.

let mut window_builder = video.window(name, width, height);
window_builder.position_centered();
/* etc. */
let window = window_builder.build().unwrap();

let mut canvas_builder = window.into_canvas();
canvas_builder = canvas_builder.present_vsync();
/* etc */
let canvas = canvas_builder.build().unwrap();

I don't really have any strong arguments for doing things one way or the other and don't know which is "more correct," and I guess it's kind of a non-issue since the differences will most often be hidden, but it just seems awkward that it's inconsistent. Changing it could potentially be breaking though, so maybe it's stuck. Thoughts?

[Cobrand]

Changing it could potentially be breaking though, so maybe it's stuck. Thoughts?

That's the whole issue. Usually builder patterns take mut self instead of &mut self, that's why we did it for Canvas, but applying that change to WindowBuilder would be a (not important) breaking change, and it would probably be unwelcome as well.

[BeefaloKing]

I guess that's good to know. Thanks for the reply.

Like I said, it does seem like a non-issue. If the change would be too breaking to be worth the consistency, it's probably safe to close this.