| // Copyright 2017 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. |
| |
| // Tests for RFC 1268: we allow overlapping impls of marker traits, |
| // that is, traits with #[marker]. In this case, a type `T` is |
| // `MyMarker` if it is either `Debug` or `Display`. |
| |
| #![feature(marker_trait_attr)] |
| |
| use std::fmt::{Debug, Display}; |
| |
| #[marker] trait MyMarker {} |
| |
| impl<T: Debug> MyMarker for T {} |
| impl<T: Display> MyMarker for T {} |
| |
| fn foo<T: MyMarker>(t: T) -> T { |
| t |
| } |
| |
| fn main() { |
| // Debug && Display: |
| assert_eq!(1, foo(1)); |
| assert_eq!(2.0, foo(2.0)); |
| |
| // Debug && !Display: |
| assert_eq!(vec![1], foo(vec![1])); |
| } |
