| // Copyright 2016 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. |
| |
| // We need to opt into the `!` feature in order to trigger the |
| // requirement that this is testing. |
| #![feature(never_type)] |
| |
| #![allow(unused)] |
| |
| trait Deserialize: Sized { |
| fn deserialize() -> Result<Self, String>; |
| } |
| |
| impl Deserialize for () { |
| fn deserialize() -> Result<(), String> { |
| Ok(()) |
| } |
| } |
| |
| trait ImplementedForUnitButNotNever {} |
| |
| impl ImplementedForUnitButNotNever for () {} |
| |
| fn foo<T: ImplementedForUnitButNotNever>(_t: T) {} |
| //~^ NOTE required by `foo` |
| |
| fn smeg() { |
| let _x = return; |
| foo(_x); |
| //~^ ERROR the trait bound |
| //~| NOTE the trait `ImplementedForUnitButNotNever` is not implemented |
| //~| NOTE the trait is implemented for `()` |
| } |
| |
| fn main() { |
| smeg(); |
| } |
| |