Correctly suggest std or core path depending if this is a no_std crate

[GuillaumeGomez]

A few lints emit suggestions using std paths whether or not this is a no_std crate, which is an issue when running rustfix afterwards. So in case this is an item that is defined in both std and core, we need to check if the crate is no_std to emit the right path.

r? @llogiq

changelog: Correctly suggest std or core path depending if this is a no_std crate

[GuillaumeGomez]

This method comes from slices so doesn't make much sense to only write Vec::.

[GuillaumeGomez]

Same here.

[llogiq]

I wonder if a helper method that returns std outside no_std code and its argument (which could be "core" or "alloc") inside would markedly simplify the code here.

Otherwise the change looks good to me.

[GuillaumeGomez]

I thought about it as well, but I'm not sure what's the best course of action here for the arguments. Few ideas I had:

std_core_path("cmp::Ord") -> "core::cmp::Ord"
std_core_path(&["cmp", "Ord"]) -> "core::cmp::Ord"
std_core_path(&["std", "cmp", "Ord"]) -> "core::cmp::Ord"

A preference maybe?

[llogiq]

Since most usages will be used in formatting anyway, a function that returns either "std" or the given argument should cater for all uses.

[GuillaumeGomez]

Let's go for get_std_core_prefix.

[GuillaumeGomez]

Oh there is already std_or_core. Let's use this one then!

[GuillaumeGomez]

Updated!

[llogiq]

Thank you!

@bors r+

[bors]

📌 Commit 874f851 has been approved by llogiq

It is now in the queue for this repository.

[bors]

⌛ Testing commit 874f851 with merge ecb0311...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: llogiq
Pushing ecb0311 to master...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: llogiq
Pushing ecb0311 to master...