Alias Pattern
Any pattern can be bound to an extra new name via an alias pattern. The syntax is pattern as name. In this example, we use this feature to preserve the original tuples while pattern matching them.
fn main {
let (a, (b, _) as tuple, _) as triple = (1, (true, 5), false)
println("a: \{a}, b: \{b}")
println("tuple: \{tuple}")
println("triple: \{triple}")
}