Should switching to using Drop trait implimentations instead of closures be considered?

[nodeSpace]

currently closures are used everywhere in egui, but they have a few limitations: https://stackoverflow.com/questions/36379242/mutably-borrow-one-struct-field-while-borrowing-another-in-a-closure

Most of egui closures are used to do some startup operations, and then execute the closure, and finally some closing operations.
This seems like a good usecase for the rust Drop trait: https://doc.rust-lang.org/std/ops/trait.Drop.html
(for example you could do:

{
let ui = ui.horizontal();
//lots of ui code
} //<--drop function is called here

//instead of
ui.horizontal(|ui| {
//lots of ui code
});

Do you think it would be worthwhile to switch to this more elegant method?
Can this even be considered a more elegant method in the first place?

[emilk]

When I first designed egui this was something I did consider, but it has drawback on its own:

• it is "magic": you don't explicitly call drop, so the code is less clear
• it requires each Ui to have a mutable reference to its parent Ui, adding a lot of complexity on its own

---

Ideally I'd like to have something similar to the Python construct with:

with ui = ui.horizontal() {
    //lots of ui code
}

…but I doubt Rust will be getting that anytime soon.

---

The multiple-borrows of a struct member can be worked around by doing a deconstruct:

fn ui(&mut self, ui: &mut Ui) {
    let Self { foo, bar, baz } = self:
    …
}

This works for most cases I've encountered.