| // 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. |
| |
| #![feature(never_type)] |
| #![feature(exhaustive_patterns, rustc_attrs)] |
| #![warn(unreachable_code)] |
| #![warn(unreachable_patterns)] |
| |
| enum Void {} |
| |
| impl From<Void> for i32 { |
| fn from(v: Void) -> i32 { |
| match v {} |
| } |
| } |
| |
| fn bar(x: Result<!, i32>) -> Result<u32, i32> { |
| x? |
| } |
| |
| fn foo(x: Result<!, i32>) -> Result<u32, i32> { |
| let y = (match x { Ok(n) => Ok(n as u32), Err(e) => Err(e) })?; |
| //~^ WARN unreachable pattern |
| //~| WARN unreachable expression |
| Ok(y) |
| } |
| |
| fn qux(x: Result<u32, Void>) -> Result<u32, i32> { |
| Ok(x?) |
| } |
| |
| fn vom(x: Result<u32, Void>) -> Result<u32, i32> { |
| let y = (match x { Ok(n) => Ok(n), Err(e) => Err(e) })?; |
| //~^ WARN unreachable pattern |
| Ok(y) |
| } |
| |
| #[rustc_error] |
| fn main() { //~ ERROR: compilation successful |
| let _ = bar(Err(123)); |
| let _ = foo(Err(123)); |
| let _ = qux(Ok(123)); |
| let _ = vom(Ok(123)); |
| } |
| |