TypeVisitor: use `ControlFlow` in rustc_{mir,privacy,traits,typeck}

2 files changed, 7 insertions, 5 deletions

diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index 5ca0fc0c88b..9862bc297be 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -42,6 +42,7 @@ use rustc_span::def_id::DefId;
 use chalk_ir::{FnSig, ForeignDefId};
 use rustc_hir::Unsafety;
 use std::collections::btree_map::{BTreeMap, Entry};
+use std::ops::ControlFlow;
 
 /// Essentially an `Into` with a `&RustInterner` parameter
 crate trait LowerInto<'tcx, T> {
@@ -897,14 +898,14 @@ impl<'tcx> BoundVarsCollector<'tcx> {
 }
 
 impl<'tcx> TypeVisitor<'tcx> for BoundVarsCollector<'tcx> {
-    fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> bool {
+    fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> ControlFlow<(), ()> {
         self.binder_index.shift_in(1);
         let result = t.super_visit_with(self);
         self.binder_index.shift_out(1);
         result
     }
 
-    fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
+    fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<(), ()> {
         match *t.kind() {
             ty::Bound(debruijn, bound_ty) if debruijn == self.binder_index => {
                 match self.parameters.entry(bound_ty.var.as_u32()) {
@@ -924,7 +925,7 @@ impl<'tcx> TypeVisitor<'tcx> for BoundVarsCollector<'tcx> {
         t.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: Region<'tcx>) -> bool {
+    fn visit_region(&mut self, r: Region<'tcx>) -> ControlFlow<(), ()> {
         match r {
             ty::ReLateBound(index, br) if *index == self.binder_index => match br {
                 ty::BoundRegion::BrNamed(def_id, _name) => {
@@ -1114,7 +1115,7 @@ impl PlaceholdersCollector {
 }
 
 impl<'tcx> TypeVisitor<'tcx> for PlaceholdersCollector {
-    fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
+    fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<(), ()> {
         match t.kind() {
             ty::Placeholder(p) if p.universe == self.universe_index => {
                 self.next_ty_placeholder = self.next_ty_placeholder.max(p.name.as_usize() + 1);
@@ -1126,7 +1127,7 @@ impl<'tcx> TypeVisitor<'tcx> for PlaceholdersCollector {
         t.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: Region<'tcx>) -> bool {
+    fn visit_region(&mut self, r: Region<'tcx>) -> ControlFlow<(), ()> {
         match r {
             ty::RePlaceholder(p) if p.universe == self.universe_index => {
                 if let ty::BoundRegion::BrAnon(anon) = p.name {
diff --git a/compiler/rustc_traits/src/lib.rs b/compiler/rustc_traits/src/lib.rs
index d0b05beb4e6..7b688cd3e21 100644
--- a/compiler/rustc_traits/src/lib.rs
+++ b/compiler/rustc_traits/src/lib.rs
@@ -4,6 +4,7 @@
 #![feature(crate_visibility_modifier)]
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
+#![feature(control_flow_enum)]
 #![recursion_limit = "256"]
 
 #[macro_use]