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// run-pass
// Test references to the trait `Stream` in the bounds for associated
// types defined on `Stream`. Issue #20551.
trait Stream {
type Car;
type Cdr: Stream;
fn car(&self) -> Self::Car;
fn cdr(self) -> Self::Cdr;
}
impl Stream for () {
type Car = ();
type Cdr = ();
fn car(&self) -> () { () }
fn cdr(self) -> () { self }
}
impl<T,U> Stream for (T, U)
where T : Clone, U : Stream
{
type Car = T;
type Cdr = U;
fn car(&self) -> T { self.0.clone() }
fn cdr(self) -> U { self.1 }
}
fn main() {
let p = (22, (44, (66, ())));
assert_eq!(p.car(), 22);
let p = p.cdr();
assert_eq!(p.car(), 44);
let p = p.cdr();
assert_eq!(p.car(), 66);
}
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