3 files changed, 17 insertions, 14 deletions
diff --git a/compiler/rustc_const_eval/src/check_consts/ops.rs b/compiler/rustc_const_eval/src/check_consts/ops.rs
index c6361710ac9..259114dbdc2 100644
--- a/compiler/rustc_const_eval/src/check_consts/ops.rs
+++ b/compiler/rustc_const_eval/src/check_consts/ops.rs
@@ -384,7 +384,7 @@ impl<'tcx> NonConstOp<'tcx> for HeapAllocation {
         ccx.dcx().create_err(errors::UnallowedHeapAllocations {
             span,
             kind: ccx.const_kind(),
-            teach: ccx.tcx.sess.teach(E0010).then_some(()),
+            teach: ccx.tcx.sess.teach(E0010),
         })
     }
 }
@@ -444,16 +444,16 @@ impl<'tcx> NonConstOp<'tcx> for CellBorrow {
         if let hir::ConstContext::Static(_) = ccx.const_kind() {
             ccx.dcx().create_err(errors::InteriorMutableDataRefer {
                 span,
-                opt_help: Some(()),
+                opt_help: true,
                 kind: ccx.const_kind(),
-                teach: ccx.tcx.sess.teach(E0492).then_some(()),
+                teach: ccx.tcx.sess.teach(E0492),
             })
         } else {
             ccx.dcx().create_err(errors::InteriorMutableDataRefer {
                 span,
-                opt_help: None,
+                opt_help: false,
                 kind: ccx.const_kind(),
-                teach: ccx.tcx.sess.teach(E0492).then_some(()),
+                teach: ccx.tcx.sess.teach(E0492),
             })
         }
     }
@@ -481,12 +481,12 @@ impl<'tcx> NonConstOp<'tcx> for MutBorrow {
             hir::BorrowKind::Raw => ccx.tcx.dcx().create_err(errors::UnallowedMutableRaw {
                 span,
                 kind: ccx.const_kind(),
-                teach: ccx.tcx.sess.teach(E0764).then_some(()),
+                teach: ccx.tcx.sess.teach(E0764),
             }),
             hir::BorrowKind::Ref => ccx.dcx().create_err(errors::UnallowedMutableRefs {
                 span,
                 kind: ccx.const_kind(),
-                teach: ccx.tcx.sess.teach(E0764).then_some(()),
+                teach: ccx.tcx.sess.teach(E0764),
             }),
         }
     }
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs
index a075bdc1911..c3d94ca0e59 100644
--- a/compiler/rustc_const_eval/src/const_eval/machine.rs
+++ b/compiler/rustc_const_eval/src/const_eval/machine.rs
@@ -40,7 +40,10 @@ const TINY_LINT_TERMINATOR_LIMIT: usize = 20;
 /// power of two of interpreted terminators.
 const PROGRESS_INDICATOR_START: usize = 4_000_000;
 
-/// Extra machine state for CTFE, and the Machine instance
+/// Extra machine state for CTFE, and the Machine instance.
+//
+// Should be public because out-of-tree rustc consumers need this
+// if they want to interact with constant values.
 pub struct CompileTimeMachine<'tcx> {
     /// The number of terminators that have been evaluated.
     ///
@@ -160,7 +163,7 @@ impl<K: Hash + Eq, V> interpret::AllocMap<K, V> for FxIndexMap<K, V> {
     }
 }
 
-pub(crate) type CompileTimeInterpCx<'tcx> = InterpCx<'tcx, CompileTimeMachine<'tcx>>;
+pub type CompileTimeInterpCx<'tcx> = InterpCx<'tcx, CompileTimeMachine<'tcx>>;
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 pub enum MemoryKind {
diff --git a/compiler/rustc_const_eval/src/errors.rs b/compiler/rustc_const_eval/src/errors.rs
index 7afb92c08ec..6075f3f84cd 100644
--- a/compiler/rustc_const_eval/src/errors.rs
+++ b/compiler/rustc_const_eval/src/errors.rs
@@ -151,7 +151,7 @@ pub(crate) struct UnallowedMutableRefs {
     pub span: Span,
     pub kind: ConstContext,
     #[note(const_eval_teach_note)]
-    pub teach: Option<()>,
+    pub teach: bool,
 }
 
 #[derive(Diagnostic)]
@@ -161,7 +161,7 @@ pub(crate) struct UnallowedMutableRaw {
     pub span: Span,
     pub kind: ConstContext,
     #[note(const_eval_teach_note)]
-    pub teach: Option<()>,
+    pub teach: bool,
 }
 #[derive(Diagnostic)]
 #[diag(const_eval_non_const_fmt_macro_call, code = E0015)]
@@ -196,7 +196,7 @@ pub(crate) struct UnallowedHeapAllocations {
     pub span: Span,
     pub kind: ConstContext,
     #[note(const_eval_teach_note)]
-    pub teach: Option<()>,
+    pub teach: bool,
 }
 
 #[derive(Diagnostic)]
@@ -214,10 +214,10 @@ pub(crate) struct InteriorMutableDataRefer {
     #[label]
     pub span: Span,
     #[help]
-    pub opt_help: Option<()>,
+    pub opt_help: bool,
     pub kind: ConstContext,
     #[note(const_eval_teach_note)]
-    pub teach: Option<()>,
+    pub teach: bool,
 }
 
 #[derive(Diagnostic)]