rustc/infer: readability improvements

Author: ljedrz

src/librustc/infer/canonical/query_result.rs

@@ -499,24 +499,22 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> {
                     let ty::OutlivesPredicate(k1, r2) = constraint.skip_binder(); // restored below
                     let k1 = substitute_value(self.tcx, result_subst, k1);
                     let r2 = substitute_value(self.tcx, result_subst, r2);
-                    match k1.unpack() {
-                        UnpackedKind::Lifetime(r1) => Obligation::new(
-                            cause.clone(),
-                            param_env,
-                            ty::Predicate::RegionOutlives(ty::Binder::dummy(
-                                ty::OutlivesPredicate(r1, r2),
+
+                    Obligation::new(
+                        cause.clone(),
+                        param_env,
+                        match k1.unpack() {
+                            UnpackedKind::Lifetime(r1) => ty::Predicate::RegionOutlives(
+                                ty::Binder::dummy(
+                                    ty::OutlivesPredicate(r1, r2)
                             )),
-                        ),
-
-                        UnpackedKind::Type(t1) => Obligation::new(
-                            cause.clone(),
-                            param_env,
-                            ty::Predicate::TypeOutlives(ty::Binder::dummy(ty::OutlivesPredicate(
-                                t1, r2,
-                            ))),
-                        ),
-                    }
-                }),
+                            UnpackedKind::Type(t1) => ty::Predicate::TypeOutlives(
+                                ty::Binder::dummy(ty::OutlivesPredicate(
+                                    t1, r2
+                            )))
+                        }
+                    )
+                })
         ) as Box<dyn Iterator<Item = _>>
     }
 

src/librustc/infer/equate.rs

@@ -77,24 +77,22 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx>
         match (&a.sty, &b.sty) {
             (&ty::Infer(TyVar(a_id)), &ty::Infer(TyVar(b_id))) => {
                 infcx.type_variables.borrow_mut().equate(a_id, b_id);
-                Ok(a)
             }
 
             (&ty::Infer(TyVar(a_id)), _) => {
                 self.fields.instantiate(b, RelationDir::EqTo, a_id, self.a_is_expected)?;
-                Ok(a)
             }
 
             (_, &ty::Infer(TyVar(b_id))) => {
                 self.fields.instantiate(a, RelationDir::EqTo, b_id, self.a_is_expected)?;
-                Ok(a)
             }
 
             _ => {
                 self.fields.infcx.super_combine_tys(self, a, b)?;
-                Ok(a)
             }
         }
+
+        Ok(a)
     }
 
     fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>)

src/librustc/infer/error_reporting/nice_region_error/util.rs

@@ -137,8 +137,8 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> {
     pub(super) fn is_self_anon(&self, is_first: bool, scope_def_id: DefId) -> bool {
         is_first
             && self.tcx
-                .opt_associated_item(scope_def_id)
-                .map(|i| i.method_has_self_argument) == Some(true)
+                   .opt_associated_item(scope_def_id)
+                   .map(|i| i.method_has_self_argument) == Some(true)
     }
 
 }

src/librustc/infer/resolve.rs

@@ -153,8 +153,8 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for FullTypeResolver<'a, 'gcx, 'tcx>
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
         if !t.needs_infer() && !ty::keep_local(&t) {
             t // micro-optimize -- if there is nothing in this type that this fold affects...
-                // ^ we need to have the `keep_local` check to un-default
-                // defaulted tuples.
+              // ^ we need to have the `keep_local` check to un-default
+              // defaulted tuples.
         } else {
             let t = self.infcx.shallow_resolve(t);
             match t.sty {