Lint: is_ascii_digit instead of is_digit

[camsteffen]

What it does

Finds usages of is_digit that can be replaced with is_ascii_digit or is_ascii_hexdigit.

Categories (optional)

• Kind: style

It is simpler since the radix does not need to be specified.

Drawbacks

None.

Example

fn bad(c: char) {
    c.is_digit(10);
    c.is_digit(16);
}

Could be written as:

fn good(c: char) {
    c.is_ascii_digit();
    c.is_ascii_hexdigit();
}

[rajcspsg]

can I work on this issue?

[camsteffen]

@rajcspsg go for it!

[bengsparks]

@camsteffen
This issue seems to not have made much progress.
Can I submit my solution instead?

[camsteffen]

I think @rajcspsg is still working on this at #6400.

[pitaj]

@rustbot claim