`almost_swapped`'s suggested alternative could be Rustier

almost_swapped will catch this faulty code which doesn't quite swap two variables:

fn main() {
    let mut a = 2;
    let mut b = 3;
    a = b;
    b = a;
    println!("a: {}, b: {}", a, b);
}

error: this looks like you are trying to swap `a` and `b`
 --> src/main.rs:4:5
  |
4 | /     a = b;
5 | |     b = a;
  | |_________^ help: try: `std::mem::swap(&mut a, &mut b)`
  |
  = note: or maybe you should use `std::mem::replace`?
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#almost_swapped
  = note: `#[deny(clippy::almost_swapped)]` on by default

It suggests doing this instead: std::mem::swap(&mut a, &mut b)

At least for smaller values, I'd suggest changing this to

(a, b) = (b, a);

as this seems clearer and more idiomatic to me. Of course this runs the risk of copying around on the stack, but that should be the compilers job to avoid I reckon.

Start by reading the almost_swapped lint documentation and its current diagnostic output in the rust-clippy repository. Compare the suggested std::mem::swap form with the proposed tuple-assignment form, including the stated copying concern. Done means the lint's recommendation is updated if the project accepts the change, with coverage for the resulting diagnostic.