change `FnMutDelegate` to trait objects

[rust.git] / compiler / rustc_middle / src / ty / fold.rs

diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs
index cb46a9dba579fd6d40a75e0b835cba021d2a7661..1297b90b4f6007de13359f1a0d40965270a35c82 100644 (file)
--- a/compiler/rustc_middle/src/ty/fold.rs
+++ b/compiler/rustc_middle/src/ty/fold.rs
@@ -377,17 +377,13 @@ pub trait BoundVarReplacerDelegate<'tcx> {
     fn replace_const(&mut self, bv: ty::BoundVar, ty: Ty<'tcx>) -> ty::Const<'tcx>;
 }
 
-pub struct FnMutDelegate<R, T, C> {
-    pub regions: R,
-    pub types: T,
-    pub consts: C,
+pub struct FnMutDelegate<'a, 'tcx> {
+    pub regions: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a),
+    pub types: &'a mut (dyn FnMut(ty::BoundTy) -> Ty<'tcx> + 'a),
+    pub consts: &'a mut (dyn FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx> + 'a),
 }
-impl<'tcx, R, T, C> BoundVarReplacerDelegate<'tcx> for FnMutDelegate<R, T, C>
-where
-    R: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
-    T: FnMut(ty::BoundTy) -> Ty<'tcx>,
-    C: FnMut(ty::BoundVar, Ty<'tcx>) -> ty::Const<'tcx>,
-{
+
+impl<'a, 'tcx> BoundVarReplacerDelegate<'tcx> for FnMutDelegate<'a, 'tcx> {
     fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx> {
         (self.regions)(br)
     }
@@ -511,7 +507,7 @@ pub fn replace_late_bound_regions<T, F>(
     pub fn replace_late_bound_regions_uncached<T, F>(
         self,
         value: Binder<'tcx, T>,
-        replace_regions: F,
+        mut replace_regions: F,
     ) -> T
     where
         F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
@@ -522,9 +518,9 @@ pub fn replace_late_bound_regions_uncached<T, F>(
             value
         } else {
             let delegate = FnMutDelegate {
-                regions: replace_regions,
-                types: |b| bug!("unexpected bound ty in binder: {b:?}"),
-                consts: |b, ty| bug!("unexpected bound ct in binder: {b:?} {ty}"),
+                regions: &mut replace_regions,
+                types: &mut |b| bug!("unexpected bound ty in binder: {b:?}"),
+                consts: &mut |b, ty| bug!("unexpected bound ct in binder: {b:?} {ty}"),
             };
             let mut replacer = BoundVarReplacer::new(self, delegate);
             value.fold_with(&mut replacer)
@@ -584,19 +580,19 @@ pub fn shift_bound_var_indices<T>(self, bound_vars: usize, value: T) -> T
         self.replace_escaping_bound_vars_uncached(
             value,
             FnMutDelegate {
-                regions: |r: ty::BoundRegion| {
+                regions: &mut |r: ty::BoundRegion| {
                     self.mk_region(ty::ReLateBound(
                         ty::INNERMOST,
                         ty::BoundRegion { var: shift_bv(r.var), kind: r.kind },
                     ))
                 },
-                types: |t: ty::BoundTy| {
+                types: &mut |t: ty::BoundTy| {
                     self.mk_ty(ty::Bound(
                         ty::INNERMOST,
                         ty::BoundTy { var: shift_bv(t.var), kind: t.kind },
                     ))
                 },
-                consts: |c, ty: Ty<'tcx>| {
+                consts: &mut |c, ty: Ty<'tcx>| {
                     self.mk_const(ty::ConstS {
                         kind: ty::ConstKind::Bound(ty::INNERMOST, shift_bv(c)),
                         ty,