src/tools/rustfmt/tests/target/fn_args_layout-vertical.rs

// rustfmt-fn_params_layout: Vertical

// Empty list should stay on one line.
fn do_bar() -> u8 {
    bar()
}

// A single argument should stay on the same line.
fn do_bar(a: u8) -> u8 {
    bar()
}

// Multiple arguments should each get their own line.
fn do_bar(
    a: u8,
    mut b: u8,
    c: &u8,
    d: &mut u8,
    closure: &Fn(i32) -> i32,
) -> i32 {
    // This feature should not affect closures.
    let bar = |x: i32, y: i32| -> i32 { x + y };
    bar(a, b)
}

// If the first argument doesn't fit on the same line with the function name,
// the whole list should probably be pushed to the next line with hanging
// indent. That's not what happens though, so check current behaviour instead.
// In any case, it should maintain single argument per line.
fn do_this_that_and_the_other_thing(
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa: u8,
    b: u8,
    c: u8,
    d: u8,
) {
    this();
    that();
    the_other_thing();
}