Mark both PyArray and PyArrayDescr as repr(transparent) to make them strictly layout-compatible with PyAny.

Author: adamreichold

src/array.rs

@@ -16,9 +16,9 @@ use ndarray::{
 };
 use num_traits::AsPrimitive;
 use pyo3::{
-    ffi, pyobject_native_type_named, type_object, types::PyModule, AsPyPointer, FromPyObject,
-    IntoPy, Py, PyAny, PyClassInitializer, PyDowncastError, PyErr, PyNativeType, PyObject,
-    PyResult, PyTypeInfo, Python, ToPyObject,
+    ffi, pyobject_native_type_named, types::PyModule, AsPyPointer, FromPyObject, IntoPy, Py, PyAny,
+    PyClassInitializer, PyDowncastError, PyErr, PyNativeType, PyObject, PyResult, PyTypeInfo,
+    Python, ToPyObject,
 };
 
 use crate::borrow::{PyReadonlyArray, PyReadwriteArray};
@@ -95,6 +95,7 @@ use crate::slice_container::PySliceContainer;
 ///
 /// [ndarray]: https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html
 /// [pyo3-memory]: https://pyo3.rs/main/memory.html
+#[repr(transparent)]
 pub struct PyArray<T, D>(PyAny, PhantomData<T>, PhantomData<D>);
 
 /// Zero-dimensional array.
@@ -119,10 +120,6 @@ pub fn get_array_module(py: Python<'_>) -> PyResult<&PyModule> {
     PyModule::import(py, npyffi::array::MOD_NAME)
 }
 
-unsafe impl<T, D> type_object::PyLayout<PyArray<T, D>> for npyffi::PyArrayObject {}
-
-impl<T, D> type_object::PySizedLayout<PyArray<T, D>> for npyffi::PyArrayObject {}
-
 unsafe impl<T: Element, D: Dimension> PyTypeInfo for PyArray<T, D> {
     type AsRefTarget = Self;
 

src/dtype.rs

@@ -45,6 +45,7 @@ pub use num_complex::{Complex32, Complex64};
 /// ```
 ///
 /// [dtype]: https://numpy.org/doc/stable/reference/generated/numpy.dtype.html
+#[repr(transparent)]
 pub struct PyArrayDescr(PyAny);
 
 pyobject_native_type_named!(PyArrayDescr);
@@ -61,12 +62,7 @@ unsafe impl PyTypeInfo for PyArrayDescr {
     }
 
     fn is_type_of(ob: &PyAny) -> bool {
-        unsafe {
-            ffi::PyObject_TypeCheck(
-                ob.as_ptr(),
-                PY_ARRAY_API.get_type_object(ob.py(), NpyTypes::PyArrayDescr_Type),
-            ) > 0
-        }
+        unsafe { ffi::PyObject_TypeCheck(ob.as_ptr(), Self::type_object_raw(ob.py())) > 0 }
     }
 }