Inherited always has TypeckResults available

compiler/rustc_typeck/src/check/inherited.rs

@@ -1,5 +1,4 @@
 use super::callee::DeferredCallResolution;
-use super::MaybeInProgressTables;
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
@@ -29,7 +28,7 @@ use std::ops::Deref;
 pub struct Inherited<'a, 'tcx> {
     pub(super) infcx: InferCtxt<'a, 'tcx>,
 
-    pub(super) typeck_results: super::MaybeInProgressTables<'a, 'tcx>,
+    pub(super) typeck_results: &'a RefCell<ty::TypeckResults<'tcx>>,
 
     pub(super) locals: RefCell<HirIdMap<super::LocalTy<'tcx>>>,
 
@@ -110,11 +109,11 @@ impl<'a, 'tcx> Inherited<'a, 'tcx> {
         let tcx = infcx.tcx;
         let item_id = tcx.hir().local_def_id_to_hir_id(def_id);
         let body_id = tcx.hir().maybe_body_owned_by(item_id);
+        let typeck_results =
+            infcx.in_progress_typeck_results.expect("building `FnCtxt` without typeck results");
 
         Inherited {
-            typeck_results: MaybeInProgressTables {
-                maybe_typeck_results: infcx.in_progress_typeck_results,
-            },
+            typeck_results,
             infcx,
             fulfillment_cx: RefCell::new(<dyn TraitEngine<'_>>::new(tcx)),
             locals: RefCell::new(Default::default()),

compiler/rustc_typeck/src/check/mod.rs

@@ -128,8 +128,7 @@ use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
 use rustc_trait_selection::traits::error_reporting::recursive_type_with_infinite_size_error;
 use rustc_trait_selection::traits::error_reporting::suggestions::ReturnsVisitor;
-
-use std::cell::{Ref, RefCell, RefMut};
+use std::cell::RefCell;
 
 use crate::require_c_abi_if_c_variadic;
 use crate::util::common::indenter;
@@ -900,32 +899,6 @@ enum TupleArgumentsFlag {
     TupleArguments,
 }
 
-/// A wrapper for `InferCtxt`'s `in_progress_typeck_results` field.
-#[derive(Copy, Clone)]
-struct MaybeInProgressTables<'a, 'tcx> {
-    maybe_typeck_results: Option<&'a RefCell<ty::TypeckResults<'tcx>>>,
-}
-
-impl<'a, 'tcx> MaybeInProgressTables<'a, 'tcx> {
-    fn borrow(self) -> Ref<'a, ty::TypeckResults<'tcx>> {
-        match self.maybe_typeck_results {
-            Some(typeck_results) => typeck_results.borrow(),
-            None => bug!(
-                "MaybeInProgressTables: inh/fcx.typeck_results.borrow() with no typeck results"
-            ),
-        }
-    }
-
-    fn borrow_mut(self) -> RefMut<'a, ty::TypeckResults<'tcx>> {
-        match self.maybe_typeck_results {
-            Some(typeck_results) => typeck_results.borrow_mut(),
-            None => bug!(
-                "MaybeInProgressTables: inh/fcx.typeck_results.borrow_mut() with no typeck results"
-            ),
-        }
-    }
-}
-
 fn typeck_item_bodies(tcx: TyCtxt<'_>, (): ()) {
     tcx.hir().par_body_owners(|body_owner_def_id| tcx.ensure().typeck(body_owner_def_id));
 }