// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #![feature(box_patterns)] #![feature(box_syntax)] #![allow(dead_code)] #![allow(unused_variables)] #![deny(unreachable_patterns)] enum IntList { Cons(isize, Box), Nil } fn tail(source_list: &IntList) -> IntList { match source_list { &IntList::Cons(val, box ref next_list) => tail(next_list), &IntList::Cons(val, box IntList::Nil) => IntList::Cons(val, box IntList::Nil), //~^ ERROR unreachable pattern _ => panic!() } } fn main() {}