Feature request: chain_tokens instead of chain_width

[RandomInsano]

Hey there! I've started handing over my code to rustfmt and it's working almost perfectly but I find that chain_width isn't doing what I'd like.

In general, I split chains when the number of function calls is greater than 3 as it helps me better understand what the chunk of code is doing at a glance. If the chain is only two functions but their names are absurdly long it's clear enough. Here's an example from my own codebase where I'm hitting this sort of thing. I'm not sure if others are hitting this as well, but I'm finding it's making my code less readable in a way I can't easily fix.

let authors = env!("CARGO_PKG_AUTHORS")
    .split(":")
    .map(|x| x.to_string())
    .collect(),

Now:

let authors = env!("CARGO_PKG_AUTHORS").split(":").map(|x| x.to_string()).collect(),

There also doesn't seem to be a way to disable it? So my option is careful inspection.

[ytmimi]

Similar feature requests have been asked for in the past (#3538, #2263). Your best bet is to use #[rustfmt::skip] if you need more control over chain formatting for now.