| // Copyright 2015 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 two distinct impls which match subtypes of one another |
| // yield coherence errors (or not) depending on the variance. |
| |
| trait Contravariant { |
| fn foo(&self) { } |
| } |
| |
| impl Contravariant for for<'a,'b> fn(&'a u8, &'b u8) -> &'a u8 { |
| } |
| |
| impl Contravariant for for<'a> fn(&'a u8, &'a u8) -> &'a u8 { |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| trait Covariant { |
| fn foo(&self) { } |
| } |
| |
| impl Covariant for for<'a,'b> fn(&'a u8, &'b u8) -> &'a u8 { |
| } |
| |
| impl Covariant for for<'a> fn(&'a u8, &'a u8) -> &'a u8 { |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| trait Invariant { |
| fn foo(&self) { } |
| } |
| |
| impl Invariant for for<'a,'b> fn(&'a u8, &'b u8) -> &'a u8 { |
| } |
| |
| impl Invariant for for<'a> fn(&'a u8, &'a u8) -> &'a u8 { |
| } |
| |
| fn main() { } |