rustfmt incompatibility: possibly missing a comma here

[Dushistov]

pub fn f(a: i16, b: f64) -> [f64; 3] {
    const C: f64 = 100.;
    [
        b,
        -b,
        match a {
            0x17 => 1.,
            0x18 => 2.,
            _ => 3.,
        } * C
            / 60.,
    ]
}

for such code clippy (from rustup/stable | 0.0.212) clippy show error:

error: possibly missing a comma here
  --> src/lib.rs:10:14
   |
10 |         } * C
   |              ^
   |

the problem that this is default coding style from rustfmt that comes with rustup/stable compiler,
it is possible to fix if reformat code like this * C / 60. , but rustfmt doesn't allow such coding style by default.

Not sure is this rustfmt issue or clippy, but clippy and rustfmt runs on CI,
and clippy fails.

[mcarton]

I would say rustfmt is the one that's wrong on this one. The style it proposes it really ugly.
Alternatively, I'd suggest you use a variable for the match, as I don't think using match as an expression like this will ever look really nice.

[topecongiro]

I think that there is an error on both clippy and rustfmt. rustfmt should either put * C on its own line or put * C / 60., on a single line, and clippy should not error on this.

[basil-cow]

Fixed by this pr, can be closed @flip1995