Add missing example for Display::fmt

[GuillaumeGomez]

r? @frewsxcv

[frewsxcv]

This is slightly confusing because it looks like a Debug representation. How do you feel about getting rid of the Foo:: in the outputted string?

[GuillaumeGomez]

I always add the enum's name first in case you have multiple wrappings:

enum Foo {
    A,
}

enum X {
    A(Foo),
}

enum Y {
    A(X),
}

[frewsxcv]

I think you're mixing up Debug and Display. Display is for user-facing output. Users shouldn't care about enum namespacing. We don't want to encourage Rust developers to implement Display if their types aren't mean to be displayed to end-users.
How about this as the example:

struct Position {
    longitude: f32,
    latitude: f32,
}

impl fmt::Display for Position {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "({}, {})", self.longitude, self.latitude)
    }
}

This seems a little more realistic than Foo and Bar and Stack ;)

[GuillaumeGomez]

Why so cruel? :O

[GuillaumeGomez]

Updated.

[frewsxcv]

@bors r+ rollup

[bors]

📌 Commit a5a3981 has been approved by frewsxcv