add more tests

src/lib.rs

@@ -132,7 +132,8 @@ impl TypeErasedVec {
         let layout = self.layout;
         let res = self.try_as_type();
 
-        if cfg!(debug_assertions) && res.is_none() {
+        #[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,

src/tests.rs

@@ -368,3 +368,21 @@ fn test_multiple_compatible_type_casts() {
     let restored = unsafe { erased.cast_into_vec::<i32>() };
     assert_eq!(restored, vec![-1, 42]);
 }
+
+#[test]
+fn test_cast_and_clear() {
+    let mut vec = Vec::<i32>::new();
+    vec.push(-1);
+    let mut erased = TypeErasedVec::new(vec);
+
+    {
+        let mut guard = unsafe { erased.cast_type::<u32>() };
+        assert_eq!(guard.as_slice(), &[u32::MAX]);
+        guard.clear();
+        guard.push(u32::MAX - 1);
+        guard.push(42);
+    }
+
+    let restored = unsafe { erased.cast_into_vec::<i32>() };
+    assert_eq!(restored, vec![-2, 42]);
+}