tests/target/trailing_commas.rs

// rustfmt-match_block_trailing_comma: true
// rustfmt-trailing_comma: Always

fn main() {
    match foo {
        x => {},
        y => {
            foo();
        },
        _ => x,
    }
}

fn f<S, T>(x: T, y: S) -> T
    where T: P,
          S: Q,
{
    x
}

impl Trait for T
    where T: P,
{
    fn f(x: T) -> T
        where T: Q + R,
    {
        x
    }
}

struct Pair<S, T>
    where T: P,
          S: P + Q,
{
    a: T,
    b: S,
}

struct TupPair<S, T>(S, T)
    where T: P,
          S: P + Q;

enum E<S, T>
    where S: P,
          T: P,
{
    A { a: T, },
}

type Double<T>
    where T: P,
          T: Q = Pair<T, T>;

extern "C" {
    fn f<S, T>(x: T, y: S) -> T
        where T: P,
              S: Q;
}

trait Q<S, T>
    where T: P,
          S: R,
{
    fn f<U, V>(self, x: T, y: S, z: U) -> Self
        where U: P,
              V: P;
}