PyO3 · mattiapenati · Mar 12, 2026 · Mar 12, 2026 · Mar 12, 2026 · Mar 12, 2026
diff --git a/src/array.rs b/src/array.rs
@@ -129,7 +129,7 @@ unsafe impl<T: Element, D: Dimension> PyTypeInfo for PyArray<T, D> {
     const MODULE: Option<&'static str> = Some("numpy");
 
     fn type_object_raw<'py>(py: Python<'py>) -> *mut ffi::PyTypeObject {
-        unsafe { npyffi::PY_ARRAY_API.get_type_object(py, npyffi::NpyTypes::PyArray_Type) }
+        unsafe { npyffi::get_type_object(py, npyffi::NpyTypes::PyArray_Type) }
     }
 
     fn is_type_of(ob: &Bound<'_, PyAny>) -> bool {
@@ -233,7 +233,7 @@ impl<T: Element, D: Dimension> PyArray<T, D> {
         let mut dims = dims.into_dimension();
         let ptr = PY_ARRAY_API.PyArray_NewFromDescr(
             py,
-            PY_ARRAY_API.get_type_object(py, npyffi::NpyTypes::PyArray_Type),
+            npyffi::get_type_object(py, npyffi::NpyTypes::PyArray_Type),
             T::get_dtype(py).into_dtype_ptr(),
             dims.ndim_cint(),
             dims.as_dims_ptr(),
@@ -259,7 +259,7 @@ impl<T: Element, D: Dimension> PyArray<T, D> {
         let mut dims = dims.into_dimension();
         let ptr = PY_ARRAY_API.PyArray_NewFromDescr(
             py,
-            PY_ARRAY_API.get_type_object(py, npyffi::NpyTypes::PyArray_Type),
+            npyffi::get_type_object(py, npyffi::NpyTypes::PyArray_Type),
             T::get_dtype(py).into_dtype_ptr(),
             dims.ndim_cint(),
             dims.as_dims_ptr(),

diff --git a/src/dtype.rs b/src/dtype.rs
@@ -17,7 +17,7 @@ use pyo3::{
 };
 
 use crate::npyffi::{
-    NpyTypes, PyArray_Descr, PyDataType_ALIGNMENT, PyDataType_ELSIZE, PyDataType_FIELDS,
+    self, NpyTypes, PyArray_Descr, PyDataType_ALIGNMENT, PyDataType_ELSIZE, PyDataType_FIELDS,
     PyDataType_FLAGS, PyDataType_NAMES, PyDataType_SUBARRAY, NPY_ALIGNED_STRUCT,
     NPY_BYTEORDER_CHAR, NPY_ITEM_HASOBJECT, NPY_TYPES, PY_ARRAY_API,
 };
@@ -58,7 +58,7 @@ unsafe impl PyTypeInfo for PyArrayDescr {
 
     #[inline]
     fn type_object_raw<'py>(py: Python<'py>) -> *mut ffi::PyTypeObject {
-        unsafe { PY_ARRAY_API.get_type_object(py, NpyTypes::PyArrayDescr_Type) }
+        unsafe { npyffi::get_type_object(py, NpyTypes::PyArrayDescr_Type) }
     }
 }
 

diff --git a/src/npyffi/array.rs b/src/npyffi/array.rs
diff --git a/src/npyffi/flags.rs b/src/npyffi/flags.rs
@@ -1,4 +1,4 @@
-use super::npy_uint32;
+use super::{npy_uint32, npy_uint64};
 use std::os::raw::c_int;
 
 pub const NPY_ARRAY_C_CONTIGUOUS: c_int = 0x0001;
@@ -11,8 +11,8 @@ pub const NPY_ARRAY_ELEMENTSTRIDES: c_int = 0x0080;
 pub const NPY_ARRAY_ALIGNED: c_int = 0x0100;
 pub const NPY_ARRAY_NOTSWAPPED: c_int = 0x0200;
 pub const NPY_ARRAY_WRITEABLE: c_int = 0x0400;
-pub const NPY_ARRAY_UPDATEIFCOPY: c_int = 0x1000;
 pub const NPY_ARRAY_WRITEBACKIFCOPY: c_int = 0x2000;
+pub const NPY_ARRAY_ENSURENOCOPY: c_int = 0x4000;
 pub const NPY_ARRAY_BEHAVED: c_int = NPY_ARRAY_ALIGNED | NPY_ARRAY_WRITEABLE;
 pub const NPY_ARRAY_BEHAVED_NS: c_int = NPY_ARRAY_BEHAVED | NPY_ARRAY_NOTSWAPPED;
 pub const NPY_ARRAY_CARRAY: c_int = NPY_ARRAY_C_CONTIGUOUS | NPY_ARRAY_BEHAVED;
@@ -22,13 +22,14 @@ pub const NPY_ARRAY_FARRAY_RO: c_int = NPY_ARRAY_F_CONTIGUOUS | NPY_ARRAY_ALIGNE
 pub const NPY_ARRAY_DEFAULT: c_int = NPY_ARRAY_CARRAY;
 pub const NPY_ARRAY_IN_ARRAY: c_int = NPY_ARRAY_CARRAY_RO;
 pub const NPY_ARRAY_OUT_ARRAY: c_int = NPY_ARRAY_CARRAY;
-pub const NPY_ARRAY_INOUT_ARRAY: c_int = NPY_ARRAY_CARRAY | NPY_ARRAY_UPDATEIFCOPY;
+pub const NPY_ARRAY_INOUT_ARRAY: c_int = NPY_ARRAY_CARRAY;
 pub const NPY_ARRAY_INOUT_ARRAY2: c_int = NPY_ARRAY_CARRAY | NPY_ARRAY_WRITEBACKIFCOPY;
 pub const NPY_ARRAY_IN_FARRAY: c_int = NPY_ARRAY_FARRAY_RO;
 pub const NPY_ARRAY_OUT_FARRAY: c_int = NPY_ARRAY_FARRAY;
-pub const NPY_ARRAY_INOUT_FARRAY: c_int = NPY_ARRAY_FARRAY | NPY_ARRAY_UPDATEIFCOPY;
+pub const NPY_ARRAY_INOUT_FARRAY: c_int = NPY_ARRAY_FARRAY;
 pub const NPY_ARRAY_INOUT_FARRAY2: c_int = NPY_ARRAY_FARRAY | NPY_ARRAY_WRITEBACKIFCOPY;
-pub const NPY_ARRAY_UPDATE_ALL: c_int = NPY_ARRAY_C_CONTIGUOUS | NPY_ARRAY_F_CONTIGUOUS;
+pub const NPY_ARRAY_UPDATE_ALL: c_int =
+    NPY_ARRAY_C_CONTIGUOUS | NPY_ARRAY_F_CONTIGUOUS | NPY_ARRAY_ALIGNED;
 
 pub const NPY_ITER_C_INDEX: npy_uint32 = 0x00000001;
 pub const NPY_ITER_F_INDEX: npy_uint32 = 0x00000002;
@@ -63,19 +64,18 @@ pub const NPY_ITER_OVERLAP_ASSUME_ELEMENTWISE: npy_uint32 = 0x40000000;
 pub const NPY_ITER_GLOBAL_FLAGS: npy_uint32 = 0x0000ffff;
 pub const NPY_ITER_PER_OP_FLAGS: npy_uint32 = 0xffff0000;
 
-pub const NPY_ITEM_REFCOUNT: u64 = 0x01;
-pub const NPY_ITEM_HASOBJECT: u64 = 0x01;
-pub const NPY_LIST_PICKLE: u64 = 0x02;
-pub const NPY_ITEM_IS_POINTER: u64 = 0x04;
-pub const NPY_NEEDS_INIT: u64 = 0x08;
-pub const NPY_NEEDS_PYAPI: u64 = 0x10;
-pub const NPY_USE_GETITEM: u64 = 0x20;
-pub const NPY_USE_SETITEM: u64 = 0x40;
-#[allow(overflowing_literals)]
-pub const NPY_ALIGNED_STRUCT: u64 = 0x80;
-pub const NPY_FROM_FIELDS: u64 =
+pub const NPY_ITEM_REFCOUNT: npy_uint64 = 0x01;
+pub const NPY_ITEM_HASOBJECT: npy_uint64 = 0x01;
+pub const NPY_LIST_PICKLE: npy_uint64 = 0x02;
+pub const NPY_ITEM_IS_POINTER: npy_uint64 = 0x04;
+pub const NPY_NEEDS_INIT: npy_uint64 = 0x08;
+pub const NPY_NEEDS_PYAPI: npy_uint64 = 0x10;
+pub const NPY_USE_GETITEM: npy_uint64 = 0x20;
+pub const NPY_USE_SETITEM: npy_uint64 = 0x40;
+pub const NPY_ALIGNED_STRUCT: npy_uint64 = 0x80;
+pub const NPY_FROM_FIELDS: npy_uint64 =
     NPY_NEEDS_INIT | NPY_LIST_PICKLE | NPY_ITEM_REFCOUNT | NPY_NEEDS_PYAPI;
-pub const NPY_OBJECT_DTYPE_FLAGS: u64 = NPY_LIST_PICKLE
+pub const NPY_OBJECT_DTYPE_FLAGS: npy_uint64 = NPY_LIST_PICKLE
     | NPY_USE_GETITEM
     | NPY_ITEM_IS_POINTER
     | NPY_ITEM_REFCOUNT

diff --git a/src/npyffi/mod.rs b/src/npyffi/mod.rs
@@ -11,44 +11,40 @@
 
 use std::mem::forget;
 use std::os::raw::{c_uint, c_void};
+use std::ptr::NonNull;
 
 use pyo3::{
+    ffi::PyTypeObject,
     sync::PyOnceLock,
     types::{PyAnyMethods, PyCapsule, PyCapsuleMethods, PyModule},
     PyResult, Python,
 };
 
-pub const API_VERSION_2_0: c_uint = 0x00000012;
-
 static API_VERSION: PyOnceLock<c_uint> = PyOnceLock::new();
 
 fn get_numpy_api<'py>(
     py: Python<'py>,
     module: &str,
     capsule: &str,
-) -> PyResult<*const *const c_void> {
+) -> PyResult<NonNull<*const c_void>> {
     let module = PyModule::import(py, module)?;
     let capsule = module.getattr(capsule)?.cast_into::<PyCapsule>()?;
 
-    let api = capsule
-        .pointer_checked(None)?
-        .cast::<*const c_void>()
-        .as_ptr()
-        .cast_const();
+    let api = capsule.pointer_checked(None)?;
 
     // Intentionally leak a reference to the capsule
     // so we can safely cache a pointer into its interior.
     forget(capsule);
 
-    Ok(api)
+    Ok(api.cast())
 }
 
 /// Returns whether the runtime `numpy` version is 2.0 or greater.
 pub fn is_numpy_2<'py>(py: Python<'py>) -> bool {
     let api_version = *API_VERSION.get_or_init(py, || unsafe {
         PY_ARRAY_API.PyArray_GetNDArrayCFeatureVersion(py)
     });
-    api_version >= API_VERSION_2_0
+    api_version >= NPY_2_0_API_VERSION
 }
 
 // Implements wrappers for NumPy's Array and UFunc API
@@ -57,52 +53,90 @@ macro_rules! impl_api {
     [$offset: expr; $fname: ident ($($arg: ident: $t: ty),* $(,)?) $(-> $ret: ty)?] => {
         #[allow(non_snake_case)]
         pub unsafe fn $fname<'py>(&self, py: Python<'py>, $($arg : $t), *) $(-> $ret)* {
-            let fptr = self.get(py, $offset) as *const extern "C" fn ($($arg : $t), *) $(-> $ret)*;
-            (*fptr)($($arg), *)
+            let f: extern "C" fn ($($arg : $t), *) $(-> $ret)* = self.get(py, $offset).cast().read();
+            f($($arg), *)
         }
     };
+}
 
-    // API with version constraints, checked at runtime
-    [$offset: expr; NumPy1; $fname: ident ($($arg: ident: $t: ty),* $(,)?) $(-> $ret: ty)?] => {
-        #[allow(non_snake_case)]
-        pub unsafe fn $fname<'py>(&self, py: Python<'py>, $($arg : $t), *) $(-> $ret)* {
-            assert!(
-                !is_numpy_2(py),
-                "{} requires API < {:08X} (NumPy 1) but the runtime version is API {:08X}",
-                stringify!($fname),
-                API_VERSION_2_0,
-                *API_VERSION.get(py).expect("API_VERSION is initialized"),
-            );
-            let fptr = self.get(py, $offset) as *const extern "C" fn ($($arg: $t), *) $(-> $ret)*;
-            (*fptr)($($arg), *)
-        }
+// Define type objects associated with the NumPy API
+macro_rules! impl_array_type {
+    ($(($api:ident [ $offset:expr ] , $tname:ident)),* $(,)?) => {
+        /// All type objects exported by the NumPy API.
+        #[allow(non_camel_case_types)]
+        pub enum NpyTypes { $($tname),* }
 
-    };
-    [$offset: expr; NumPy2; $fname: ident ($($arg: ident: $t: ty),* $(,)?) $(-> $ret: ty)?] => {
-        #[allow(non_snake_case)]
-        pub unsafe fn $fname<'py>(&self, py: Python<'py>, $($arg : $t), *) $(-> $ret)* {
-            assert!(
-                is_numpy_2(py),
-                "{} requires API {:08X} or greater (NumPy 2) but the runtime version is API {:08X}",
-                stringify!($fname),
-                API_VERSION_2_0,
-                *API_VERSION.get(py).expect("API_VERSION is initialized"),
-            );
-            let fptr = self.get(py, $offset) as *const extern "C" fn ($($arg: $t), *) $(-> $ret)*;
-            (*fptr)($($arg), *)
+        /// Get a pointer of the type object associated with `ty`.
+        pub unsafe fn get_type_object<'py>(py: Python<'py>, ty: NpyTypes) -> *mut PyTypeObject {
+            match ty {
+                $( NpyTypes::$tname => $api.get(py, $offset).read() as _ ),*
+            }
         }
+    }
+}
 
-    };
+impl_array_type! {
+    // Multiarray API
+    // Slot 1 was never meaningfully used by NumPy
+    (PY_ARRAY_API[2], PyArray_Type),
+    (PY_ARRAY_API[3], PyArrayDescr_Type),
+    // Unused slot 4, was `PyArrayFlags_Type`
+    (PY_ARRAY_API[5], PyArrayIter_Type),
+    (PY_ARRAY_API[6], PyArrayMultiIter_Type),
+    // (PY_ARRAY_API[7], NPY_NUMUSERTYPES) -> c_int,
+    (PY_ARRAY_API[8], PyBoolArrType_Type),
+    // (PY_ARRAY_API[9], _PyArrayScalar_BoolValues) -> *mut PyBoolScalarObject,
+    (PY_ARRAY_API[10], PyGenericArrType_Type),
+    (PY_ARRAY_API[11], PyNumberArrType_Type),
+    (PY_ARRAY_API[12], PyIntegerArrType_Type),
+    (PY_ARRAY_API[13], PySignedIntegerArrType_Type),
+    (PY_ARRAY_API[14], PyUnsignedIntegerArrType_Type),
+    (PY_ARRAY_API[15], PyInexactArrType_Type),
+    (PY_ARRAY_API[16], PyFloatingArrType_Type),
+    (PY_ARRAY_API[17], PyComplexFloatingArrType_Type),
+    (PY_ARRAY_API[18], PyFlexibleArrType_Type),
+    (PY_ARRAY_API[19], PyCharacterArrType_Type),
+    (PY_ARRAY_API[20], PyByteArrType_Type),
+    (PY_ARRAY_API[21], PyShortArrType_Type),
+    (PY_ARRAY_API[22], PyIntArrType_Type),
+    (PY_ARRAY_API[23], PyLongArrType_Type),
+    (PY_ARRAY_API[24], PyLongLongArrType_Type),
+    (PY_ARRAY_API[25], PyUByteArrType_Type),
+    (PY_ARRAY_API[26], PyUShortArrType_Type),
+    (PY_ARRAY_API[27], PyUIntArrType_Type),
+    (PY_ARRAY_API[28], PyULongArrType_Type),
+    (PY_ARRAY_API[29], PyULongLongArrType_Type),
+    (PY_ARRAY_API[30], PyFloatArrType_Type),
+    (PY_ARRAY_API[31], PyDoubleArrType_Type),
+    (PY_ARRAY_API[32], PyLongDoubleArrType_Type),
+    (PY_ARRAY_API[33], PyCFloatArrType_Type),
+    (PY_ARRAY_API[34], PyCDoubleArrType_Type),
+    (PY_ARRAY_API[35], PyCLongDoubleArrType_Type),
+    (PY_ARRAY_API[36], PyObjectArrType_Type),
+    (PY_ARRAY_API[37], PyStringArrType_Type),
+    (PY_ARRAY_API[38], PyUnicodeArrType_Type),
+    (PY_ARRAY_API[39], PyVoidArrType_Type),
+    (PY_ARRAY_API[214], PyTimeIntegerArrType_Type),
+    (PY_ARRAY_API[215], PyDatetimeArrType_Type),
+    (PY_ARRAY_API[216], PyTimedeltaArrType_Type),
+    (PY_ARRAY_API[217], PyHalfArrType_Type),
+    (PY_ARRAY_API[218], NpyIter_Type),
+    // UFunc API
+    (PY_UFUNC_API[0], PyUFunc_Type),
 }
 
 pub mod array;
 pub mod flags;
+mod npy_common;
+mod numpyconfig;
 pub mod objects;
 pub mod types;
 pub mod ufunc;
 
 pub use self::array::*;
 pub use self::flags::*;
+pub use self::npy_common::*;
+pub use self::numpyconfig::*;
 pub use self::objects::*;
 pub use self::types::*;
 pub use self::ufunc::*;
diff --git a/src/npyffi/npy_common.rs b/src/npyffi/npy_common.rs
@@ -0,0 +1,8 @@
+use std::ffi::c_int;
+
+/// Unknown CPU endianness.
+pub const NPY_CPU_UNKNOWN_ENDIAN: c_int = 0;
+/// CPU is little-endian.
+pub const NPY_CPU_LITTLE: c_int = 1;
+/// CPU is big-endian.
+pub const NPY_CPU_BIG: c_int = 2;
diff --git a/src/npyffi/numpyconfig.rs b/src/npyffi/numpyconfig.rs
@@ -0,0 +1,18 @@
+// This file matches the numpyconfig.h header.
+
+use std::ffi::c_uint;
+
+/// The current target ABI version
+const NPY_ABI_VERSION: c_uint = 0x02000000;
+
+/// The current target API version (v1.15)
+const NPY_API_VERSION: c_uint = 0x0000000c;
+
+pub(super) const NPY_2_0_API_VERSION: c_uint = 0x00000012;
+
+/// The current version of the `ndarray` object (ABI version).
+pub const NPY_VERSION: c_uint = NPY_ABI_VERSION;
+/// The current version of C API.
+pub const NPY_FEATURE_VERSION: c_uint = NPY_API_VERSION;
+/// The string representation of current version C API.
+pub const NPY_FEATURE_VERSION_STRING: &str = "1.15";