rust/src/test/run-pass/impl-for-never.rs
2016-08-13 21:37:09 +08:00

37 lines
1020 B
Rust

// Copyright 2012 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.
// Test that we can call static methods on ! both directly and when it appears in a generic
#![feature(never_type)]
trait StringifyType {
fn stringify_type() -> &'static str;
}
impl StringifyType for ! {
fn stringify_type() -> &'static str {
"!"
}
}
fn maybe_stringify<T: StringifyType>(opt: Option<T>) -> &'static str {
match opt {
Some(_) => T::stringify_type(),
None => "none",
}
}
fn main() {
println!("! is {}", <!>::stringify_type());
println!("None is {}", maybe_stringify(None::<!>));
}