Rollup merge of #87504 - ehuss:update-mdbook, r=Mark-Simulacrum

[rust.git] / compiler / rustc_typeck / src / collect.rs

diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index 46b3ec5cf40c774ce5259e3892b9c62c7918c3d0..ce74d6fec9eae95deadc97795c8f2773e19bc4cf 100644 (file)
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -129,6 +129,16 @@ fn visit_ty(&mut self, t: &'v hir::Ty<'v>) {
         }
         intravisit::walk_ty(self, t)
     }
+    fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
+        match generic_arg {
+            hir::GenericArg::Infer(inf) => {
+                self.0.push(inf.span);
+                intravisit::walk_inf(self, inf);
+            }
+            hir::GenericArg::Type(t) => self.visit_ty(t),
+            _ => {}
+        }
+    }
 }
 
 struct CollectItemTypesVisitor<'tcx> {
@@ -1714,13 +1724,11 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
 }
 
 fn are_suggestable_generic_args(generic_args: &[hir::GenericArg<'_>]) -> bool {
-    generic_args
-        .iter()
-        .filter_map(|arg| match arg {
-            hir::GenericArg::Type(ty) => Some(ty),
-            _ => None,
-        })
-        .any(is_suggestable_infer_ty)
+    generic_args.iter().any(|arg| match arg {
+        hir::GenericArg::Type(ty) => is_suggestable_infer_ty(ty),
+        hir::GenericArg::Infer(_) => true,
+        _ => false,
+    })
 }
 
 /// Whether `ty` is a type with `_` placeholders that can be inferred. Used in diagnostics only to
@@ -2222,7 +2230,9 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
                             let constness = match modifier {
                                 hir::TraitBoundModifier::MaybeConst => hir::Constness::NotConst,
                                 hir::TraitBoundModifier::None => constness,
-                                hir::TraitBoundModifier::Maybe => bug!("this wasn't handled"),
+                                // We ignore `where T: ?Sized`, it is already part of
+                                // type parameter `T`.
+                                hir::TraitBoundModifier::Maybe => continue,
                             };
 
                             let mut bounds = Bounds::default();
@@ -2252,6 +2262,8 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
                             predicates.extend(bounds.predicates(tcx, ty));
                         }
 
+                        hir::GenericBound::Unsized(_) => {}
+
                         hir::GenericBound::Outlives(lifetime) => {
                             let region =
                                 <dyn AstConv<'_>>::ast_region_to_region(&icx, lifetime, None);
@@ -2513,6 +2525,7 @@ fn predicates_from_bound<'tcx>(
             );
             bounds.predicates(astconv.tcx(), param_ty)
         }
+        hir::GenericBound::Unsized(_) => vec![],
         hir::GenericBound::Outlives(ref lifetime) => {
             let region = astconv.ast_region_to_region(lifetime, None);
             let pred = ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(param_ty, region))