How to parse `{` and `}` characters?

[fritzrehde]

Suppose I would like to use:

#[derive(FromStr)]
#[display("{{a},{b}}")]
struct Ratingss {
    a: usize,
    b: usize,
}

to parse from the string "{42,100}". This leads to an invalid display format. Is this a bug, or not allowed/not implemented?

[frozenlib]

In parse-display, just like in std::fmt::format, { and } must be expressed as {{ and }}. So, it should be written as follows.

#[derive(FromStr, Debug)]
#[display("{{{a},{b}}}")]
struct Ratingss {
    a: usize,
    b: usize,
}

[fritzrehde]

Ah thanks, I didn't know that about the syntax to print { und } in std::fmt::format.