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#![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() { }
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