Pull tcx out into a local variable

Author: oli-obk

compiler/rustc_ty_utils/src/opaque_types.rs

@@ -118,8 +118,10 @@ impl<'tcx> OpaqueTypeCollector<'tcx> {
             return;
         }
 
+        let tcx = self.tcx;
+
         // TAITs outside their defining scopes are ignored.
-        let origin = self.tcx.opaque_type_origin(alias_ty.def_id.expect_local());
+        let origin = tcx.opaque_type_origin(alias_ty.def_id.expect_local());
         trace!(?origin);
         match origin {
             rustc_hir::OpaqueTyOrigin::FnReturn(_) | rustc_hir::OpaqueTyOrigin::AsyncFn(_) => {}
@@ -134,12 +136,11 @@ impl<'tcx> OpaqueTypeCollector<'tcx> {
 
         self.opaques.push(alias_ty.def_id.expect_local());
 
-        let parent_count = self.tcx.generics_of(alias_ty.def_id).parent_count;
+        let parent_count = tcx.generics_of(alias_ty.def_id).parent_count;
         // Only check that the parent generics of the TAIT/RPIT are unique.
         // the args owned by the opaque are going to always be duplicate
         // lifetime params for RPITs, and empty for TAITs.
-        match self
-            .tcx
+        match tcx
             .uses_unique_generic_params(&alias_ty.args[..parent_count], CheckRegions::FromFunction)
         {
             Ok(()) => {
@@ -150,27 +151,25 @@ impl<'tcx> OpaqueTypeCollector<'tcx> {
                 // Collect opaque types nested within the associated type bounds of this opaque type.
                 // We use identity args here, because we already know that the opaque type uses
                 // only generic parameters, and thus instantiating would not give us more information.
-                for (pred, span) in self
-                    .tcx
-                    .explicit_item_bounds(alias_ty.def_id)
-                    .instantiate_identity_iter_copied()
+                for (pred, span) in
+                    tcx.explicit_item_bounds(alias_ty.def_id).instantiate_identity_iter_copied()
                 {
                     trace!(?pred);
                     self.visit(span, pred);
                 }
             }
             Err(NotUniqueParam::NotParam(arg)) => {
-                self.tcx.dcx().emit_err(NotParam {
+                tcx.dcx().emit_err(NotParam {
                     arg,
                     span: self.span(),
-                    opaque_span: self.tcx.def_span(alias_ty.def_id),
+                    opaque_span: tcx.def_span(alias_ty.def_id),
                 });
             }
             Err(NotUniqueParam::DuplicateParam(arg)) => {
-                self.tcx.dcx().emit_err(DuplicateArg {
+                tcx.dcx().emit_err(DuplicateArg {
                     arg,
                     span: self.span(),
-                    opaque_span: self.tcx.def_span(alias_ty.def_id),
+                    opaque_span: tcx.def_span(alias_ty.def_id),
                 });
             }
         }