rust/src/test/run-pass/issue-6318.rs

// Copyright 2013 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

pub enum Thing {
    A(~Foo)
}

pub trait Foo {}

pub struct Struct;

impl Foo for Struct {}

pub fn main() {
    match A(~Struct as ~Foo) {
        A(_a) => 0,
    };
}