The nested-or-pattern for matching combines | expressions.
Example if statement without nested-or-pattern:
if let Some(2) | Some(3) | Some(5) | Some(7) = value {…}And with nested-or-pattern:
if let Some(2 | 3 | 5 | 7) = value …The nested-or-pattern can be useful in many kinds of statements.
Example match statement:
match value {
Some(n @ (2 | 3 | 5 | 7)) => println!("{n} is a prime"),
…Example let statement:
let (Ok(i) | Err(i)) = [1, 2, 3].binary_search(&2);Example function definition:
fn f((Ok(i) | Err(i)): Result<i32, i32>) {}