Update comparison_chain lint solution to make it work with no_std as well

[GuillaumeGomez]

Fixes #11785.

Just a small sentence fix to also make it work in no_std crates.

r? @llogiq

changelog: Update comparison_chain lint solution to make it work with no_std as well

[samueltardieu]

@GuillaumeGomez I'm quite dubious about this one: except for two lints, all other lints seem to use std:: over core:: when describing the lint. As an embedded systems programmer myself, I would prefer to see core:: or alloc:: instead of std:: whenever possible, but I feel this is less friendly for beginners.

Can't we expect that people using #![no_std] usually know where to look? Or should we add a generic warning on the documentation page saying "If you use Rust in an embedded context with !#[no_std], you might want to look up the standard modules in core or allow rather than std"?

You can look at those examples for references to std which should be replaced by core in an embedded context as well:

• iter_on_single_items
• drain_collect

[GuillaumeGomez]

I'm very fine with closing this PR and the related issue as is.

[llogiq]

I think doing this in the docs is overrated. OTOH, switching the suggestions between core/alloc and std depending on whether the code has a no_std marker isn't.

[GuillaumeGomez]

Fair point.

[GuillaumeGomez]

I opened #12149 for that.