//@ run-pass // A smoke test for recursive enum structures using Box. // This test constructs a linked list-like structure to exercise memory allocation and ownership. // Originally introduced in 2010, this is one of Rust’s earliest test cases. #![allow(dead_code)] enum List { Cons(isize, Box), Nil, } fn main() { List::Cons( 10, Box::new(List::Cons( 11, Box::new(List::Cons(12, Box::new(List::Nil))), )), ); }