Merge pull request #18447 from ChayimFriedman2/cleanup-tylowerctx

Avoid interior mutability in `TyLoweringContext`

crates/hir-ty/src/chalk_db.rs

@@ -615,7 +615,7 @@ pub(crate) fn associated_ty_data_query(
     let type_alias_data = db.type_alias_data(type_alias);
     let generic_params = generics(db.upcast(), type_alias.into());
     let resolver = hir_def::resolver::HasResolver::resolver(type_alias, db.upcast());
-    let ctx =
+    let mut ctx =
         crate::TyLoweringContext::new(db, &resolver, &type_alias_data.types_map, type_alias.into())
             .with_type_param_mode(crate::lower::ParamLoweringMode::Variable);
 
@@ -627,14 +627,16 @@ pub(crate) fn associated_ty_data_query(
         .build();
     let self_ty = TyKind::Alias(AliasTy::Projection(pro_ty)).intern(Interner);
 
-    let mut bounds: Vec<_> = type_alias_data
-        .bounds
-        .iter()
-        .flat_map(|bound| ctx.lower_type_bound(bound, self_ty.clone(), false))
-        .filter_map(|pred| generic_predicate_to_inline_bound(db, &pred, &self_ty))
-        .collect();
+    let mut bounds = Vec::new();
+    for bound in &type_alias_data.bounds {
+        ctx.lower_type_bound(bound, self_ty.clone(), false).for_each(|pred| {
+            if let Some(pred) = generic_predicate_to_inline_bound(db, &pred, &self_ty) {
+                bounds.push(pred);
+            }
+        });
+    }
 
-    if !ctx.unsized_types.borrow().contains(&self_ty) {
+    if !ctx.unsized_types.contains(&self_ty) {
         let sized_trait = db
             .lang_item(resolver.krate(), LangItem::Sized)
             .and_then(|lang_item| lang_item.as_trait().map(to_chalk_trait_id));

crates/hir-ty/src/infer.rs

@@ -1420,7 +1420,7 @@ impl<'a> InferenceContext<'a> {
             Some(path) => path,
             None => return (self.err_ty(), None),
         };
-        let ctx = crate::lower::TyLoweringContext::new(
+        let mut ctx = crate::lower::TyLoweringContext::new(
             self.db,
             &self.resolver,
             &self.body.types,

crates/hir-ty/src/infer/path.rs

@@ -151,7 +151,7 @@ impl InferenceContext<'_> {
             let last = path.segments().last()?;
 
             // Don't use `self.make_ty()` here as we need `orig_ns`.
-            let ctx = crate::lower::TyLoweringContext::new(
+            let mut ctx = crate::lower::TyLoweringContext::new(
                 self.db,
                 &self.resolver,
                 &self.body.types,