| // Copyright 2012 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 we correctly infer variance for type parameters in |
| // various types and traits. |
| |
| #![feature(rustc_attrs)] |
| |
| #[rustc_variance] |
| struct TestImm<A, B> { //~ ERROR types=[[+, +];[];[]] |
| x: A, |
| y: B, |
| } |
| |
| #[rustc_variance] |
| struct TestMut<A, B:'static> { //~ ERROR types=[[+, o];[];[]] |
| x: A, |
| y: &'static mut B, |
| } |
| |
| #[rustc_variance] |
| struct TestIndirect<A:'static, B:'static> { //~ ERROR types=[[+, o];[];[]] |
| m: TestMut<A, B> |
| } |
| |
| #[rustc_variance] |
| struct TestIndirect2<A:'static, B:'static> { //~ ERROR types=[[o, o];[];[]] |
| n: TestMut<A, B>, |
| m: TestMut<B, A> |
| } |
| |
| #[rustc_variance] |
| trait Getter<A> { //~ ERROR types=[[o];[o];[]] |
| fn get(&self) -> A; |
| } |
| |
| #[rustc_variance] |
| trait Setter<A> { //~ ERROR types=[[o];[o];[]] |
| fn set(&mut self, a: A); |
| } |
| |
| #[rustc_variance] |
| trait GetterSetter<A> { //~ ERROR types=[[o];[o];[]] |
| fn get(&self) -> A; |
| fn set(&mut self, a: A); |
| } |
| |
| #[rustc_variance] |
| trait GetterInTypeBound<A> { //~ ERROR types=[[o];[o];[]] |
| // Here, the use of `A` in the method bound *does* affect |
| // variance. Think of it as if the method requested a dictionary |
| // for `T:Getter<A>`. Since this dictionary is an input, it is |
| // contravariant, and the Getter is covariant w/r/t A, yielding an |
| // overall contravariant result. |
| fn do_it<T:Getter<A>>(&self); |
| } |
| |
| #[rustc_variance] |
| trait SetterInTypeBound<A> { //~ ERROR types=[[o];[o];[]] |
| fn do_it<T:Setter<A>>(&self); |
| } |
| |
| #[rustc_variance] |
| struct TestObject<A, R> { //~ ERROR types=[[o, o];[];[]] |
| n: Box<Setter<A>+Send>, |
| m: Box<Getter<R>+Send>, |
| } |
| |
| fn main() {} |