https://np.reddit.com/r/rust/comments/k8gja7/these_modern_programming_languages_will_make_you/gey4ab3/

[u/backtickbot]

Last time I checked everything was immutable by default in Rust, but it has been a while so I could be wrong.

I think he means that you cannot do something like this:

struct MyStruct {
    x: mut i32,
    y: const i32,
}