Trait method parameters now need to have names in 2018 edition

1

The following compiles in the 2015 edition but not on the 2018 edition:

pub trait A {
    fn go(&self, u32);
}

If a name is added like so then it works on both editions:

pub trait A {
    fn go(&self, a: u32);
}

Playground link

Was this change intentional? I tried to find documentation or discussion of it, but was unable to.

2

Basically, this makes the rustdocs better, and makes it feasible to allow some things like slice patterns in method implementations in traits.

2 Likes
3

There’s an issue for this confusion from this change: #53990

1 Like
4

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