somewhat related cleanup

Author: lcnr

src/librustc_middle/ty/mod.rs

@@ -1302,7 +1302,7 @@ impl<'tcx> Predicate<'tcx> {
         // from the substitution and the value being substituted into, and
         // this trick achieves that).
 
-        let substs = &trait_ref.skip_binder().substs;
+        let substs = trait_ref.skip_binder().substs;
         let kind = self.kind();
         let new = match kind {
             &PredicateKind::Trait(ref binder, constness) => {
@@ -1555,13 +1555,6 @@ impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitRef<'tcx>> {
     }
 }
 
-impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<&PolyTraitRef<'tcx>> {
-    fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        ty::PredicateKind::Trait(self.value.to_poly_trait_predicate(), self.constness)
-            .to_predicate(tcx)
-    }
-}
-
 impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
         PredicateKind::RegionOutlives(self).to_predicate(tcx)

src/librustc_trait_selection/traits/util.rs

@@ -59,8 +59,8 @@ impl<'tcx> TraitAliasExpansionInfo<'tcx> {
         );
     }
 
-    pub fn trait_ref(&self) -> &ty::PolyTraitRef<'tcx> {
-        &self.top().0
+    pub fn trait_ref(&self) -> ty::PolyTraitRef<'tcx> {
+        self.top().0
     }
 
     pub fn top(&self) -> &(ty::PolyTraitRef<'tcx>, Span) {
@@ -109,7 +109,7 @@ impl<'tcx> TraitAliasExpander<'tcx> {
 
         // Don't recurse if this trait alias is already on the stack for the DFS search.
         let anon_pred = anonymize_predicate(tcx, pred);
-        if item.path.iter().rev().skip(1).any(|(tr, _)| {
+        if item.path.iter().rev().skip(1).any(|&(tr, _)| {
             anonymize_predicate(tcx, tr.without_const().to_predicate(tcx)) == anon_pred
         }) {
             return false;