3 files changed, 6 insertions, 7 deletions
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs
index a5bc121485d..d865d5bc974 100644
--- a/compiler/rustc_const_eval/src/const_eval/machine.rs
+++ b/compiler/rustc_const_eval/src/const_eval/machine.rs
@@ -622,10 +622,9 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
         let alloc = alloc.inner();
         if is_write {
             // Write access. These are never allowed, but we give a targeted error message.
-            if alloc.mutability == Mutability::Not {
-                Err(err_ub!(WriteToReadOnly(alloc_id)).into())
-            } else {
-                Err(ConstEvalErrKind::ModifiedGlobal.into())
+            match alloc.mutability {
+                Mutability::Not => Err(err_ub!(WriteToReadOnly(alloc_id)).into()),
+                Mutability::Mut => Err(ConstEvalErrKind::ModifiedGlobal.into()),
             }
         } else {
             // Read access. These are usually allowed, with some exceptions.
diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs
index 291bfb2b558..a87ce0053e8 100644
--- a/compiler/rustc_const_eval/src/interpret/memory.rs
+++ b/compiler/rustc_const_eval/src/interpret/memory.rs
@@ -304,7 +304,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             .into());
         };
 
-        if alloc.mutability == Mutability::Not {
+        if alloc.mutability.is_not() {
             throw_ub_format!("deallocating immutable allocation {alloc_id:?}");
         }
         if alloc_kind != kind {
@@ -631,7 +631,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         }
 
         let (_kind, alloc) = self.memory.alloc_map.get_mut(id).unwrap();
-        if alloc.mutability == Mutability::Not {
+        if alloc.mutability.is_not() {
             throw_ub!(WriteToReadOnly(id))
         }
         Ok((alloc, &mut self.machine))
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs
index a2f2457487a..72f456138ef 100644
--- a/compiler/rustc_const_eval/src/transform/validate.rs
+++ b/compiler/rustc_const_eval/src/transform/validate.rs
@@ -754,7 +754,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 // FIXME(JakobDegen) The validator should check that `self.mir_phase <
                 // DropsLowered`. However, this causes ICEs with generation of drop shims, which
                 // seem to fail to set their `MirPhase` correctly.
-                if *kind == RetagKind::Raw || *kind == RetagKind::TwoPhase {
+                if matches!(kind, RetagKind::Raw | RetagKind::TwoPhase) {
                     self.fail(location, format!("explicit `{:?}` is forbidden", kind));
                 }
             }