implement ref-level upcast and downcast

src/ptr.rs

@@ -57,14 +57,28 @@ impl<T> OwnRef<'_, T> {
 	}
 }
 
-impl OwnRef<'_, dyn Any> {
-	pub fn take<U: 'static>(mut self) -> Result<U, Self> {
+impl<'a, T: Any> OwnRef<'a, T> {
+	pub fn into_any(mut self) -> OwnRef<'a, dyn Any> {
+		let mut p = self.0.take().unwrap();
+		let p = unsafe { p.as_mut() } as &'a mut dyn Any;
+		OwnRef(Some(p.into()), PhantomData)
+	}
+}
+
+impl<'a> OwnRef<'a, dyn Any> {
+	pub fn downcast<U: 'static>(mut self) -> Result<OwnRef<'a, U>, Self> {
 		if !self.is::<U>() {
 			return Err(self);
 		}
 		let p = self.0.take().unwrap();
 		let p = p.cast::<U>();
-		Ok(unsafe { p.read() })
+		Ok(OwnRef(Some(p), PhantomData))
+	}
+}
+
+impl OwnRef<'_, dyn Any> {
+	pub fn take<U: 'static>(self) -> Result<U, Self> {
+		self.downcast::<U>().map(|r| r.take())
 	}
 }