Clarify deliberate panic paths

src/lib.rs

@@ -170,6 +170,10 @@ impl TypeErasedVec {
     ///
     /// # Panics
     /// Panics if `T` does not have the same `Layout` as the underlying capacity.
+    #[expect(
+        clippy::panic,
+        reason = "this infallible convenience method documents and reports layout mismatch"
+    )]
     pub fn as_type<T: 'static>(&mut self) -> ContentGuard<'_, T> {
         let layout = self.layout;
         self.try_as_type().unwrap_or_else(|| {
@@ -213,6 +217,10 @@ impl TypeErasedVec {
     ///
     /// # Panics
     /// Panics if `T` needs drop or does not have the erased allocation's layout.
+    #[expect(
+        clippy::panic,
+        reason = "this infallible convenience method documents and reports layout mismatch"
+    )]
     pub fn as_type_scoped<T>(&mut self) -> ContentGuard<'_, T> {
         let layout = self.layout;
         self.try_as_type_scoped().unwrap_or_else(|| {
@@ -235,15 +243,13 @@ impl TypeErasedVec {
         let layout = self.layout;
         let res = self.try_as_type();
 
-        #[cfg(debug_assertions)]
-        if res.is_none() {
-            unreachable!(
-                "Calling `as_type_unchecked` with an incompatible layout is UB! Target type layout must exactly match the erased layout. Capacity is reserved for {:?} but {} has {:?}",
-                layout,
-                std::any::type_name::<T>(),
-                Layout::new::<T>()
-            )
-        }
+        debug_assert!(
+            res.is_some(),
+            "Calling `as_type_unchecked` with an incompatible layout is UB! Target type layout must exactly match the erased layout. Capacity is reserved for {:?} but {} has {:?}",
+            layout,
+            std::any::type_name::<T>(),
+            Layout::new::<T>()
+        );
 
         // SAFETY: Ensured by the caller.
         unsafe { res.unwrap_unchecked() }