or_patterns - The Rust Unstable Book

# `or_patterns`

The tracking issue for this feature is: #54883

The `or_pattern` language feature allows `|` to be arbitrarily nested within a pattern, for example, `Some(A(0) | B(1 | 2))` becomes a valid pattern.

## Examples

    #![feature(or_patterns)]

    pub enum Foo {
        Bar,
        Baz,
        Quux,
    }

    pub fn example(maybe_foo: Option<Foo>) {
        match maybe_foo {
            Some(Foo::Bar | Foo::Baz) => {
                println!("The value contained `Bar` or `Baz`");
            }
            Some(_) => {
                println!("The value did not contain `Bar` or `Baz`");
            }
            None => {
                println!("The value was `None`");
            }
        }
    }