implement IntoPy and ToPyObject for Borrowed<T>

Author: davidhewitt

src/instance.rs

@@ -355,6 +355,19 @@ impl<T> Clone for Borrowed<'_, '_, T> {
 
 impl<T> Copy for Borrowed<'_, '_, T> {}
 
+impl<T> IntoPy<Py<PyAny>> for Borrowed<'_, '_, T> {
+    fn into_py(self, py: Python<'_>) -> Py<PyAny> {
+        // Safety: Borrowed<'_, '_, T> is a pointer to a Python object
+        unsafe { Py::from_borrowed_ptr(py, self.as_ptr()) }
+    }
+}
+
+impl<T> ToPyObject for Borrowed<'_, '_, T> {
+    fn to_object(&self, py: Python<'_>) -> Py<PyAny> {
+        (*self).into_py(py)
+    }
+}
+
 /// A GIL-independent reference to an object allocated on the Python heap.
 ///
 /// This type does not auto-dereference to the inner object because you must prove you hold the GIL to access it.

tests/ui/invalid_result_conversion.stderr

@@ -5,8 +5,8 @@ error[E0277]: the trait bound `PyErr: From<MyError>` is not satisfied
    | ^^^^^^^^^^^^^ the trait `From<MyError>` is not implemented for `PyErr`
    |
    = help: the following other types implement trait `From<T>`:
-             <PyErr as From<PyBorrowError>>
              <PyErr as From<std::io::Error>>
+             <PyErr as From<PyBorrowError>>
              <PyErr as From<PyBorrowMutError>>
              <PyErr as From<PyDowncastError<'a>>>
              <PyErr as From<DowncastError<'_, '_>>>