a: &Self,
b: &Self,
) -> RelateResult<'tcx, Self> {
- if a.len() != b.len() {
+ let tcx = relation.tcx();
+
+ // FIXME: this is wasteful, but want to do a perf run to see how slow it is.
+ // We need to perform this deduplication as we sometimes generate duplicate projections
+ // in `a`.
+ let mut a_v: Vec<_> = a.into_iter().collect();
+ let mut b_v: Vec<_> = b.into_iter().collect();
+ a_v.sort_by(|a, b| a.stable_cmp(tcx, b));
+ a_v.dedup();
+ b_v.sort_by(|a, b| a.stable_cmp(tcx, b));
+ b_v.dedup();
+ if a_v.len() != b_v.len() {
return Err(TypeError::ExistentialMismatch(expected_found(relation, a, b)));
}
- let tcx = relation.tcx();
- let v = a.iter().zip(b.iter()).map(|(ep_a, ep_b)| {
+ let v = a_v.into_iter().zip(b_v.into_iter()).map(|(ep_a, ep_b)| {
use crate::ty::ExistentialPredicate::*;
match (ep_a, ep_b) {
(Trait(ref a), Trait(ref b)) => Ok(Trait(relation.relate(a, b)?)),
--- /dev/null
+// check-pass
+trait Service {
+ type S;
+}
+
+trait Framing {
+ type F;
+}
+
+impl Framing for () {
+ type F = ();
+}
+
+trait HttpService<F: Framing>: Service<S = F::F> {}
+
+type BoxService = Box<dyn HttpService<(), S = ()>>;
+
+fn build_server<F: FnOnce() -> BoxService>(_: F) {}
+
+fn make_server<F: Framing>() -> Box<dyn HttpService<F, S = F::F>> {
+ unimplemented!()
+}
+
+fn main() {
+ build_server(|| make_server())
+}