Less ideal formatting for struct pattern matching in if let

[upsuper]

Given the following code:

struct Foo {
    something: Option<u32>,
    bar: u32,
}

fn main() {
    let a = Foo {
        something: Some(1),
        bar: 2,
    };
    if let Foo { something: Some(something), .. } = a {
        println!("{}", something);
    }
}

rustfmt formats the if let as

    if let Foo {
        something: Some(something),
        ..
    } = a
    {
        println!("{}", something);
    }

which looks rather unfortunate...

Should probably keep the original form in this case?

[upsuper]

Also I leave the configuration default, which means control_brace_style should be AlwaysSameLine, however it pushes the brace to the next line here, which seems like a bug?

[topecongiro]

control_brace_style only applies to control flows whose pattern consist of a single line. IIRC, if the pattern consists of multiple lines, then rustfmt will put the opening brace on the next line.

[remi-dupre]

Hi!

I have a few additions about this issue:

1. The same behavior is applied to match arms (or matches! macro, probably any pattern context we can think of).
2. This actually controlled by setting struct_lit_width (eg. a value of 50 instead of default 28 is enough get the result expected by @upsuper in his example).

However I still think it would make sense to provide a separate settings for actual struct literals and patterns (patterns being usually less readable if they don't fit in a single line, I think this last particular issue make it hard to use advanced pattern matching on struct enum variants with default rustfmt settings).