| #![allow(dead_code)] |
| #![feature(rustc_attrs)] |
| |
| use std::cell::Cell; |
| |
| // Check that a type parameter which is only used in a trait bound is |
| // not considered bivariant. |
| |
| #[rustc_variance] |
| struct InvariantMut<'a,A:'a,B:'a> { //~ ERROR [-, o, o] |
| t: &'a mut (A,B) |
| } |
| |
| #[rustc_variance] |
| struct InvariantCell<A> { //~ ERROR [o] |
| t: Cell<A> |
| } |
| |
| #[rustc_variance] |
| struct InvariantIndirect<A> { //~ ERROR [o] |
| t: InvariantCell<A> |
| } |
| |
| #[rustc_variance] |
| struct Covariant<A> { //~ ERROR [+] |
| t: A, u: fn() -> A |
| } |
| |
| #[rustc_variance] |
| struct Contravariant<A> { //~ ERROR [-] |
| t: fn(A) |
| } |
| |
| #[rustc_variance] |
| enum Enum<A,B,C> { //~ ERROR [+, -, o] |
| Foo(Covariant<A>), |
| Bar(Contravariant<B>), |
| Zed(Covariant<C>,Contravariant<C>) |
| } |
| |
| pub fn main() { } |