src/test/run-pass/impl-for-never.rs

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Test that we can call static methods on ! both directly and when it appears in a generic
  12
  13 #![feature(never_type)]
  14
  15 trait StringifyType {
  16     fn stringify_type() -> &'static str;
  17 }
  18
  19 impl StringifyType for ! {
  20     fn stringify_type() -> &'static str {
  21         "!"
  22     }
  23 }
  24
  25 fn maybe_stringify<T: StringifyType>(opt: Option<T>) -> &'static str {
  26     match opt {
  27         Some(_) => T::stringify_type(),
  28         None => "none",
  29     }
  30 }
  31
  32 fn main() {
  33     println!("! is {}", <!>::stringify_type());
  34     println!("None is {}", maybe_stringify(None::<!>));
  35 }
  36