1 /*
2 pybind11/numpy.h: Basic NumPy support, vectorize() wrapper
4 Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
6 All rights reserved. Use of this source code is governed by a
7 BSD-style license that can be found in the LICENSE file.
8 */
10 #pragma once
12 #include "pybind11.h"
13 #include "complex.h"
14 #include <numeric>
15 #include <algorithm>
16 #include <array>
17 #include <cstdlib>
18 #include <cstring>
19 #include <sstream>
20 #include <string>
21 #include <initializer_list>
22 #include <functional>
23 #include <utility>
24 #include <typeindex>
26 #if defined(_MSC_VER)
27 # pragma warning(push)
28 # pragma warning(disable: 4127) // warning C4127: Conditional expression is constant
29 #endif
31 /* This will be true on all flat address space platforms and allows us to reduce the
32 whole npy_intp / ssize_t / Py_intptr_t business down to just ssize_t for all size
33 and dimension types (e.g. shape, strides, indexing), instead of inflicting this
34 upon the library user. */
35 static_assert(sizeof(ssize_t) == sizeof(Py_intptr_t), "ssize_t != Py_intptr_t");
37 NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
39 class array; // Forward declaration
41 NAMESPACE_BEGIN(detail)
42 template <typename type, typename SFINAE = void> struct npy_format_descriptor;
44 struct PyArrayDescr_Proxy {
45 PyObject_HEAD
46 PyObject *typeobj;
47 char kind;
48 char type;
49 char byteorder;
50 char flags;
51 int type_num;
52 int elsize;
53 int alignment;
54 char *subarray;
55 PyObject *fields;
56 PyObject *names;
57 };
59 struct PyArray_Proxy {
60 PyObject_HEAD
61 char *data;
62 int nd;
63 ssize_t *dimensions;
64 ssize_t *strides;
65 PyObject *base;
66 PyObject *descr;
67 int flags;
68 };
70 struct PyVoidScalarObject_Proxy {
71 PyObject_VAR_HEAD
72 char *obval;
73 PyArrayDescr_Proxy *descr;
74 int flags;
75 PyObject *base;
76 };
78 struct numpy_type_info {
79 PyObject* dtype_ptr;
80 std::string format_str;
81 };
83 struct numpy_internals {
84 std::unordered_map<std::type_index, numpy_type_info> registered_dtypes;
86 numpy_type_info *get_type_info(const std::type_info& tinfo, bool throw_if_missing = true) {
87 auto it = registered_dtypes.find(std::type_index(tinfo));
88 if (it != registered_dtypes.end())
89 return &(it->second);
90 if (throw_if_missing)
91 pybind11_fail(std::string("NumPy type info missing for ") + tinfo.name());
92 return nullptr;
93 }
95 template<typename T> numpy_type_info *get_type_info(bool throw_if_missing = true) {
96 return get_type_info(typeid(typename std::remove_cv<T>::type), throw_if_missing);
97 }
98 };
100 inline PYBIND11_NOINLINE void load_numpy_internals(numpy_internals* &ptr) {
101 ptr = &get_or_create_shared_data<numpy_internals>("_numpy_internals");
102 }
104 inline numpy_internals& get_numpy_internals() {
105 static numpy_internals* ptr = nullptr;
106 if (!ptr)
107 load_numpy_internals(ptr);
108 return *ptr;
109 }
111 struct npy_api {
112 enum constants {
113 NPY_ARRAY_C_CONTIGUOUS_ = 0x0001,
114 NPY_ARRAY_F_CONTIGUOUS_ = 0x0002,
115 NPY_ARRAY_OWNDATA_ = 0x0004,
116 NPY_ARRAY_FORCECAST_ = 0x0010,
117 NPY_ARRAY_ENSUREARRAY_ = 0x0040,
118 NPY_ARRAY_ALIGNED_ = 0x0100,
119 NPY_ARRAY_WRITEABLE_ = 0x0400,
120 NPY_BOOL_ = 0,
121 NPY_BYTE_, NPY_UBYTE_,
122 NPY_SHORT_, NPY_USHORT_,
123 NPY_INT_, NPY_UINT_,
124 NPY_LONG_, NPY_ULONG_,
125 NPY_LONGLONG_, NPY_ULONGLONG_,
126 NPY_FLOAT_, NPY_DOUBLE_, NPY_LONGDOUBLE_,
127 NPY_CFLOAT_, NPY_CDOUBLE_, NPY_CLONGDOUBLE_,
128 NPY_OBJECT_ = 17,
129 NPY_STRING_, NPY_UNICODE_, NPY_VOID_
130 };
132 typedef struct {
133 Py_intptr_t *ptr;
134 int len;
135 } PyArray_Dims;
137 static npy_api& get() {
138 static npy_api api = lookup();
139 return api;
140 }
142 bool PyArray_Check_(PyObject *obj) const {
143 return (bool) PyObject_TypeCheck(obj, PyArray_Type_);
144 }
145 bool PyArrayDescr_Check_(PyObject *obj) const {
146 return (bool) PyObject_TypeCheck(obj, PyArrayDescr_Type_);
147 }
149 unsigned int (*PyArray_GetNDArrayCFeatureVersion_)();
150 PyObject *(*PyArray_DescrFromType_)(int);
151 PyObject *(*PyArray_NewFromDescr_)
152 (PyTypeObject *, PyObject *, int, Py_intptr_t *,
153 Py_intptr_t *, void *, int, PyObject *);
154 PyObject *(*PyArray_DescrNewFromType_)(int);
155 int (*PyArray_CopyInto_)(PyObject *, PyObject *);
156 PyObject *(*PyArray_NewCopy_)(PyObject *, int);
157 PyTypeObject *PyArray_Type_;
158 PyTypeObject *PyVoidArrType_Type_;
159 PyTypeObject *PyArrayDescr_Type_;
160 PyObject *(*PyArray_DescrFromScalar_)(PyObject *);
161 PyObject *(*PyArray_FromAny_) (PyObject *, PyObject *, int, int, int, PyObject *);
162 int (*PyArray_DescrConverter_) (PyObject *, PyObject **);
163 bool (*PyArray_EquivTypes_) (PyObject *, PyObject *);
164 int (*PyArray_GetArrayParamsFromObject_)(PyObject *, PyObject *, char, PyObject **, int *,
165 Py_ssize_t *, PyObject **, PyObject *);
166 PyObject *(*PyArray_Squeeze_)(PyObject *);
167 int (*PyArray_SetBaseObject_)(PyObject *, PyObject *);
168 PyObject* (*PyArray_Resize_)(PyObject*, PyArray_Dims*, int, int);
169 private:
170 enum functions {
171 API_PyArray_GetNDArrayCFeatureVersion = 211,
172 API_PyArray_Type = 2,
173 API_PyArrayDescr_Type = 3,
174 API_PyVoidArrType_Type = 39,
175 API_PyArray_DescrFromType = 45,
176 API_PyArray_DescrFromScalar = 57,
177 API_PyArray_FromAny = 69,
178 API_PyArray_Resize = 80,
179 API_PyArray_CopyInto = 82,
180 API_PyArray_NewCopy = 85,
181 API_PyArray_NewFromDescr = 94,
182 API_PyArray_DescrNewFromType = 9,
183 API_PyArray_DescrConverter = 174,
184 API_PyArray_EquivTypes = 182,
185 API_PyArray_GetArrayParamsFromObject = 278,
186 API_PyArray_Squeeze = 136,
187 API_PyArray_SetBaseObject = 282
188 };
190 static npy_api lookup() {
191 module m = module::import("numpy.core.multiarray");
192 auto c = m.attr("_ARRAY_API");
193 #if PY_MAJOR_VERSION >= 3
194 void **api_ptr = (void **) PyCapsule_GetPointer(c.ptr(), NULL);
195 #else
196 void **api_ptr = (void **) PyCObject_AsVoidPtr(c.ptr());
197 #endif
198 npy_api api;
199 #define DECL_NPY_API(Func) api.Func##_ = (decltype(api.Func##_)) api_ptr[API_##Func];
200 DECL_NPY_API(PyArray_GetNDArrayCFeatureVersion);
201 if (api.PyArray_GetNDArrayCFeatureVersion_() < 0x7)
202 pybind11_fail("pybind11 numpy support requires numpy >= 1.7.0");
203 DECL_NPY_API(PyArray_Type);
204 DECL_NPY_API(PyVoidArrType_Type);
205 DECL_NPY_API(PyArrayDescr_Type);
206 DECL_NPY_API(PyArray_DescrFromType);
207 DECL_NPY_API(PyArray_DescrFromScalar);
208 DECL_NPY_API(PyArray_FromAny);
209 DECL_NPY_API(PyArray_Resize);
210 DECL_NPY_API(PyArray_CopyInto);
211 DECL_NPY_API(PyArray_NewCopy);
212 DECL_NPY_API(PyArray_NewFromDescr);
213 DECL_NPY_API(PyArray_DescrNewFromType);
214 DECL_NPY_API(PyArray_DescrConverter);
215 DECL_NPY_API(PyArray_EquivTypes);
216 DECL_NPY_API(PyArray_GetArrayParamsFromObject);
217 DECL_NPY_API(PyArray_Squeeze);
218 DECL_NPY_API(PyArray_SetBaseObject);
219 #undef DECL_NPY_API
220 return api;
221 }
222 };
224 inline PyArray_Proxy* array_proxy(void* ptr) {
225 return reinterpret_cast<PyArray_Proxy*>(ptr);
226 }
228 inline const PyArray_Proxy* array_proxy(const void* ptr) {
229 return reinterpret_cast<const PyArray_Proxy*>(ptr);
230 }
232 inline PyArrayDescr_Proxy* array_descriptor_proxy(PyObject* ptr) {
233 return reinterpret_cast<PyArrayDescr_Proxy*>(ptr);
234 }
236 inline const PyArrayDescr_Proxy* array_descriptor_proxy(const PyObject* ptr) {
237 return reinterpret_cast<const PyArrayDescr_Proxy*>(ptr);
238 }
240 inline bool check_flags(const void* ptr, int flag) {
241 return (flag == (array_proxy(ptr)->flags & flag));
242 }
244 template <typename T> struct is_std_array : std::false_type { };
245 template <typename T, size_t N> struct is_std_array<std::array<T, N>> : std::true_type { };
246 template <typename T> struct is_complex : std::false_type { };
247 template <typename T> struct is_complex<std::complex<T>> : std::true_type { };
249 template <typename T> struct array_info_scalar {
250 typedef T type;
251 static constexpr bool is_array = false;
252 static constexpr bool is_empty = false;
253 static PYBIND11_DESCR extents() { return _(""); }
254 static void append_extents(list& /* shape */) { }
255 };
256 // Computes underlying type and a comma-separated list of extents for array
257 // types (any mix of std::array and built-in arrays). An array of char is
258 // treated as scalar because it gets special handling.
259 template <typename T> struct array_info : array_info_scalar<T> { };
260 template <typename T, size_t N> struct array_info<std::array<T, N>> {
261 using type = typename array_info<T>::type;
262 static constexpr bool is_array = true;
263 static constexpr bool is_empty = (N == 0) || array_info<T>::is_empty;
264 static constexpr size_t extent = N;
266 // appends the extents to shape
267 static void append_extents(list& shape) {
268 shape.append(N);
269 array_info<T>::append_extents(shape);
270 }
272 template<typename T2 = T, enable_if_t<!array_info<T2>::is_array, int> = 0>
273 static PYBIND11_DESCR extents() {
274 return _<N>();
275 }
277 template<typename T2 = T, enable_if_t<array_info<T2>::is_array, int> = 0>
278 static PYBIND11_DESCR extents() {
279 return concat(_<N>(), array_info<T>::extents());
280 }
281 };
282 // For numpy we have special handling for arrays of characters, so we don't include
283 // the size in the array extents.
284 template <size_t N> struct array_info<char[N]> : array_info_scalar<char[N]> { };
285 template <size_t N> struct array_info<std::array<char, N>> : array_info_scalar<std::array<char, N>> { };
286 template <typename T, size_t N> struct array_info<T[N]> : array_info<std::array<T, N>> { };
287 template <typename T> using remove_all_extents_t = typename array_info<T>::type;
289 template <typename T> using is_pod_struct = all_of<
290 std::is_standard_layout<T>, // since we're accessing directly in memory we need a standard layout type
291 #if !defined(__GNUG__) || defined(_LIBCPP_VERSION) || defined(_GLIBCXX_USE_CXX11_ABI)
292 // _GLIBCXX_USE_CXX11_ABI indicates that we're using libstdc++ from GCC 5 or newer, independent
293 // of the actual compiler (Clang can also use libstdc++, but it always defines __GNUC__ == 4).
294 std::is_trivially_copyable<T>,
295 #else
296 // GCC 4 doesn't implement is_trivially_copyable, so approximate it
297 std::is_trivially_destructible<T>,
298 satisfies_any_of<T, std::has_trivial_copy_constructor, std::has_trivial_copy_assign>,
299 #endif
300 satisfies_none_of<T, std::is_reference, std::is_array, is_std_array, std::is_arithmetic, is_complex, std::is_enum>
301 >;
303 template <ssize_t Dim = 0, typename Strides> ssize_t byte_offset_unsafe(const Strides &) { return 0; }
304 template <ssize_t Dim = 0, typename Strides, typename... Ix>
305 ssize_t byte_offset_unsafe(const Strides &strides, ssize_t i, Ix... index) {
306 return i * strides[Dim] + byte_offset_unsafe<Dim + 1>(strides, index...);
307 }
309 /**
310 * Proxy class providing unsafe, unchecked const access to array data. This is constructed through
311 * the `unchecked<T, N>()` method of `array` or the `unchecked<N>()` method of `array_t<T>`. `Dims`
312 * will be -1 for dimensions determined at runtime.
313 */
314 template <typename T, ssize_t Dims>
315 class unchecked_reference {
316 protected:
317 static constexpr bool Dynamic = Dims < 0;
318 const unsigned char *data_;
319 // Storing the shape & strides in local variables (i.e. these arrays) allows the compiler to
320 // make large performance gains on big, nested loops, but requires compile-time dimensions
321 conditional_t<Dynamic, const ssize_t *, std::array<ssize_t, (size_t) Dims>>
322 shape_, strides_;
323 const ssize_t dims_;
325 friend class pybind11::array;
326 // Constructor for compile-time dimensions:
327 template <bool Dyn = Dynamic>
328 unchecked_reference(const void *data, const ssize_t *shape, const ssize_t *strides, enable_if_t<!Dyn, ssize_t>)
329 : data_{reinterpret_cast<const unsigned char *>(data)}, dims_{Dims} {
330 for (size_t i = 0; i < (size_t) dims_; i++) {
331 shape_[i] = shape[i];
332 strides_[i] = strides[i];
333 }
334 }
335 // Constructor for runtime dimensions:
336 template <bool Dyn = Dynamic>
337 unchecked_reference(const void *data, const ssize_t *shape, const ssize_t *strides, enable_if_t<Dyn, ssize_t> dims)
338 : data_{reinterpret_cast<const unsigned char *>(data)}, shape_{shape}, strides_{strides}, dims_{dims} {}
340 public:
341 /**
342 * Unchecked const reference access to data at the given indices. For a compile-time known
343 * number of dimensions, this requires the correct number of arguments; for run-time
344 * dimensionality, this is not checked (and so is up to the caller to use safely).
345 */
346 template <typename... Ix> const T &operator()(Ix... index) const {
347 static_assert(ssize_t{sizeof...(Ix)} == Dims || Dynamic,
348 "Invalid number of indices for unchecked array reference");
349 return *reinterpret_cast<const T *>(data_ + byte_offset_unsafe(strides_, ssize_t(index)...));
350 }
351 /**
352 * Unchecked const reference access to data; this operator only participates if the reference
353 * is to a 1-dimensional array. When present, this is exactly equivalent to `obj(index)`.
354 */
355 template <ssize_t D = Dims, typename = enable_if_t<D == 1 || Dynamic>>
356 const T &operator[](ssize_t index) const { return operator()(index); }
358 /// Pointer access to the data at the given indices.
359 template <typename... Ix> const T *data(Ix... ix) const { return &operator()(ssize_t(ix)...); }
361 /// Returns the item size, i.e. sizeof(T)
362 constexpr static ssize_t itemsize() { return sizeof(T); }
364 /// Returns the shape (i.e. size) of dimension `dim`
365 ssize_t shape(ssize_t dim) const { return shape_[(size_t) dim]; }
367 /// Returns the number of dimensions of the array
368 ssize_t ndim() const { return dims_; }
370 /// Returns the total number of elements in the referenced array, i.e. the product of the shapes
371 template <bool Dyn = Dynamic>
372 enable_if_t<!Dyn, ssize_t> size() const {
373 return std::accumulate(shape_.begin(), shape_.end(), (ssize_t) 1, std::multiplies<ssize_t>());
374 }
375 template <bool Dyn = Dynamic>
376 enable_if_t<Dyn, ssize_t> size() const {
377 return std::accumulate(shape_, shape_ + ndim(), (ssize_t) 1, std::multiplies<ssize_t>());
378 }
380 /// Returns the total number of bytes used by the referenced data. Note that the actual span in
381 /// memory may be larger if the referenced array has non-contiguous strides (e.g. for a slice).
382 ssize_t nbytes() const {
383 return size() * itemsize();
384 }
385 };
387 template <typename T, ssize_t Dims>
388 class unchecked_mutable_reference : public unchecked_reference<T, Dims> {
389 friend class pybind11::array;
390 using ConstBase = unchecked_reference<T, Dims>;
391 using ConstBase::ConstBase;
392 using ConstBase::Dynamic;
393 public:
394 /// Mutable, unchecked access to data at the given indices.
395 template <typename... Ix> T& operator()(Ix... index) {
396 static_assert(ssize_t{sizeof...(Ix)} == Dims || Dynamic,
397 "Invalid number of indices for unchecked array reference");
398 return const_cast<T &>(ConstBase::operator()(index...));
399 }
400 /**
401 * Mutable, unchecked access data at the given index; this operator only participates if the
402 * reference is to a 1-dimensional array (or has runtime dimensions). When present, this is
403 * exactly equivalent to `obj(index)`.
404 */
405 template <ssize_t D = Dims, typename = enable_if_t<D == 1 || Dynamic>>
406 T &operator[](ssize_t index) { return operator()(index); }
408 /// Mutable pointer access to the data at the given indices.
409 template <typename... Ix> T *mutable_data(Ix... ix) { return &operator()(ssize_t(ix)...); }
410 };
412 template <typename T, ssize_t Dim>
413 struct type_caster<unchecked_reference<T, Dim>> {
414 static_assert(Dim == 0 && Dim > 0 /* always fail */, "unchecked array proxy object is not castable");
415 };
416 template <typename T, ssize_t Dim>
417 struct type_caster<unchecked_mutable_reference<T, Dim>> : type_caster<unchecked_reference<T, Dim>> {};
419 NAMESPACE_END(detail)
421 class dtype : public object {
422 public:
423 PYBIND11_OBJECT_DEFAULT(dtype, object, detail::npy_api::get().PyArrayDescr_Check_);
425 explicit dtype(const buffer_info &info) {
426 dtype descr(_dtype_from_pep3118()(PYBIND11_STR_TYPE(info.format)));
427 // If info.itemsize == 0, use the value calculated from the format string
428 m_ptr = descr.strip_padding(info.itemsize ? info.itemsize : descr.itemsize()).release().ptr();
429 }
431 explicit dtype(const std::string &format) {
432 m_ptr = from_args(pybind11::str(format)).release().ptr();
433 }
435 dtype(const char *format) : dtype(std::string(format)) { }
437 dtype(list names, list formats, list offsets, ssize_t itemsize) {
438 dict args;
439 args["names"] = names;
440 args["formats"] = formats;
441 args["offsets"] = offsets;
442 args["itemsize"] = pybind11::int_(itemsize);
443 m_ptr = from_args(args).release().ptr();
444 }
446 /// This is essentially the same as calling numpy.dtype(args) in Python.
447 static dtype from_args(object args) {
448 PyObject *ptr = nullptr;
449 if (!detail::npy_api::get().PyArray_DescrConverter_(args.release().ptr(), &ptr) || !ptr)
450 throw error_already_set();
451 return reinterpret_steal<dtype>(ptr);
452 }
454 /// Return dtype associated with a C++ type.
455 template <typename T> static dtype of() {
456 return detail::npy_format_descriptor<typename std::remove_cv<T>::type>::dtype();
457 }
459 /// Size of the data type in bytes.
460 ssize_t itemsize() const {
461 return detail::array_descriptor_proxy(m_ptr)->elsize;
462 }
464 /// Returns true for structured data types.
465 bool has_fields() const {
466 return detail::array_descriptor_proxy(m_ptr)->names != nullptr;
467 }
469 /// Single-character type code.
470 char kind() const {
471 return detail::array_descriptor_proxy(m_ptr)->kind;
472 }
474 private:
475 static object _dtype_from_pep3118() {
476 static PyObject *obj = module::import("numpy.core._internal")
477 .attr("_dtype_from_pep3118").cast<object>().release().ptr();
478 return reinterpret_borrow<object>(obj);
479 }
481 dtype strip_padding(ssize_t itemsize) {
482 // Recursively strip all void fields with empty names that are generated for
483 // padding fields (as of NumPy v1.11).
484 if (!has_fields())
485 return *this;
487 struct field_descr { PYBIND11_STR_TYPE name; object format; pybind11::int_ offset; };
488 std::vector<field_descr> field_descriptors;
490 for (auto field : attr("fields").attr("items")()) {
491 auto spec = field.cast<tuple>();
492 auto name = spec[0].cast<pybind11::str>();
493 auto format = spec[1].cast<tuple>()[0].cast<dtype>();
494 auto offset = spec[1].cast<tuple>()[1].cast<pybind11::int_>();
495 if (!len(name) && format.kind() == 'V')
496 continue;
497 field_descriptors.push_back({(PYBIND11_STR_TYPE) name, format.strip_padding(format.itemsize()), offset});
498 }
500 std::sort(field_descriptors.begin(), field_descriptors.end(),
501 [](const field_descr& a, const field_descr& b) {
502 return a.offset.cast<int>() < b.offset.cast<int>();
503 });
505 list names, formats, offsets;
506 for (auto& descr : field_descriptors) {
507 names.append(descr.name);
508 formats.append(descr.format);
509 offsets.append(descr.offset);
510 }
511 return dtype(names, formats, offsets, itemsize);
512 }
513 };
515 class array : public buffer {
516 public:
517 PYBIND11_OBJECT_CVT(array, buffer, detail::npy_api::get().PyArray_Check_, raw_array)
519 enum {
520 c_style = detail::npy_api::NPY_ARRAY_C_CONTIGUOUS_,
521 f_style = detail::npy_api::NPY_ARRAY_F_CONTIGUOUS_,
522 forcecast = detail::npy_api::NPY_ARRAY_FORCECAST_
523 };
525 array() : array({{0}}, static_cast<const double *>(nullptr)) {}
527 using ShapeContainer = detail::any_container<ssize_t>;
528 using StridesContainer = detail::any_container<ssize_t>;
530 // Constructs an array taking shape/strides from arbitrary container types
531 array(const pybind11::dtype &dt, ShapeContainer shape, StridesContainer strides,
532 const void *ptr = nullptr, handle base = handle()) {
534 if (strides->empty())
535 *strides = c_strides(*shape, dt.itemsize());
537 auto ndim = shape->size();
538 if (ndim != strides->size())
539 pybind11_fail("NumPy: shape ndim doesn't match strides ndim");
540 auto descr = dt;
542 int flags = 0;
543 if (base && ptr) {
544 if (isinstance<array>(base))
545 /* Copy flags from base (except ownership bit) */
546 flags = reinterpret_borrow<array>(base).flags() & ~detail::npy_api::NPY_ARRAY_OWNDATA_;
547 else
548 /* Writable by default, easy to downgrade later on if needed */
549 flags = detail::npy_api::NPY_ARRAY_WRITEABLE_;
550 }
552 auto &api = detail::npy_api::get();
553 auto tmp = reinterpret_steal<object>(api.PyArray_NewFromDescr_(
554 api.PyArray_Type_, descr.release().ptr(), (int) ndim, shape->data(), strides->data(),
555 const_cast<void *>(ptr), flags, nullptr));
556 if (!tmp)
557 throw error_already_set();
558 if (ptr) {
559 if (base) {
560 api.PyArray_SetBaseObject_(tmp.ptr(), base.inc_ref().ptr());
561 } else {
562 tmp = reinterpret_steal<object>(api.PyArray_NewCopy_(tmp.ptr(), -1 /* any order */));
563 }
564 }
565 m_ptr = tmp.release().ptr();
566 }
568 array(const pybind11::dtype &dt, ShapeContainer shape, const void *ptr = nullptr, handle base = handle())
569 : array(dt, std::move(shape), {}, ptr, base) { }
571 template <typename T, typename = detail::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>>
572 array(const pybind11::dtype &dt, T count, const void *ptr = nullptr, handle base = handle())
573 : array(dt, {{count}}, ptr, base) { }
575 template <typename T>
576 array(ShapeContainer shape, StridesContainer strides, const T *ptr, handle base = handle())
577 : array(pybind11::dtype::of<T>(), std::move(shape), std::move(strides), ptr, base) { }
579 template <typename T>
580 array(ShapeContainer shape, const T *ptr, handle base = handle())
581 : array(std::move(shape), {}, ptr, base) { }
583 template <typename T>
584 explicit array(ssize_t count, const T *ptr, handle base = handle()) : array({count}, {}, ptr, base) { }
586 explicit array(const buffer_info &info)
587 : array(pybind11::dtype(info), info.shape, info.strides, info.ptr) { }
589 /// Array descriptor (dtype)
590 pybind11::dtype dtype() const {
591 return reinterpret_borrow<pybind11::dtype>(detail::array_proxy(m_ptr)->descr);
592 }
594 /// Total number of elements
595 ssize_t size() const {
596 return std::accumulate(shape(), shape() + ndim(), (ssize_t) 1, std::multiplies<ssize_t>());
597 }
599 /// Byte size of a single element
600 ssize_t itemsize() const {
601 return detail::array_descriptor_proxy(detail::array_proxy(m_ptr)->descr)->elsize;
602 }
604 /// Total number of bytes
605 ssize_t nbytes() const {
606 return size() * itemsize();
607 }
609 /// Number of dimensions
610 ssize_t ndim() const {
611 return detail::array_proxy(m_ptr)->nd;
612 }
614 /// Base object
615 object base() const {
616 return reinterpret_borrow<object>(detail::array_proxy(m_ptr)->base);
617 }
619 /// Dimensions of the array
620 const ssize_t* shape() const {
621 return detail::array_proxy(m_ptr)->dimensions;
622 }
624 /// Dimension along a given axis
625 ssize_t shape(ssize_t dim) const {
626 if (dim >= ndim())
627 fail_dim_check(dim, "invalid axis");
628 return shape()[dim];
629 }
631 /// Strides of the array
632 const ssize_t* strides() const {
633 return detail::array_proxy(m_ptr)->strides;
634 }
636 /// Stride along a given axis
637 ssize_t strides(ssize_t dim) const {
638 if (dim >= ndim())
639 fail_dim_check(dim, "invalid axis");
640 return strides()[dim];
641 }
643 /// Return the NumPy array flags
644 int flags() const {
645 return detail::array_proxy(m_ptr)->flags;
646 }
648 /// If set, the array is writeable (otherwise the buffer is read-only)
649 bool writeable() const {
650 return detail::check_flags(m_ptr, detail::npy_api::NPY_ARRAY_WRITEABLE_);
651 }
653 /// If set, the array owns the data (will be freed when the array is deleted)
654 bool owndata() const {
655 return detail::check_flags(m_ptr, detail::npy_api::NPY_ARRAY_OWNDATA_);
656 }
658 /// Pointer to the contained data. If index is not provided, points to the
659 /// beginning of the buffer. May throw if the index would lead to out of bounds access.
660 template<typename... Ix> const void* data(Ix... index) const {
661 return static_cast<const void *>(detail::array_proxy(m_ptr)->data + offset_at(index...));
662 }
664 /// Mutable pointer to the contained data. If index is not provided, points to the
665 /// beginning of the buffer. May throw if the index would lead to out of bounds access.
666 /// May throw if the array is not writeable.
667 template<typename... Ix> void* mutable_data(Ix... index) {
668 check_writeable();
669 return static_cast<void *>(detail::array_proxy(m_ptr)->data + offset_at(index...));
670 }
672 /// Byte offset from beginning of the array to a given index (full or partial).
673 /// May throw if the index would lead to out of bounds access.
674 template<typename... Ix> ssize_t offset_at(Ix... index) const {
675 if ((ssize_t) sizeof...(index) > ndim())
676 fail_dim_check(sizeof...(index), "too many indices for an array");
677 return byte_offset(ssize_t(index)...);
678 }
680 ssize_t offset_at() const { return 0; }
682 /// Item count from beginning of the array to a given index (full or partial).
683 /// May throw if the index would lead to out of bounds access.
684 template<typename... Ix> ssize_t index_at(Ix... index) const {
685 return offset_at(index...) / itemsize();
686 }
688 /**
689 * Returns a proxy object that provides access to the array's data without bounds or
690 * dimensionality checking. Will throw if the array is missing the `writeable` flag. Use with
691 * care: the array must not be destroyed or reshaped for the duration of the returned object,
692 * and the caller must take care not to access invalid dimensions or dimension indices.
693 */
694 template <typename T, ssize_t Dims = -1> detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
695 if (Dims >= 0 && ndim() != Dims)
696 throw std::domain_error("array has incorrect number of dimensions: " + std::to_string(ndim()) +
697 "; expected " + std::to_string(Dims));
698 return detail::unchecked_mutable_reference<T, Dims>(mutable_data(), shape(), strides(), ndim());
699 }
701 /**
702 * Returns a proxy object that provides const access to the array's data without bounds or
703 * dimensionality checking. Unlike `mutable_unchecked()`, this does not require that the
704 * underlying array have the `writable` flag. Use with care: the array must not be destroyed or
705 * reshaped for the duration of the returned object, and the caller must take care not to access
706 * invalid dimensions or dimension indices.
707 */
708 template <typename T, ssize_t Dims = -1> detail::unchecked_reference<T, Dims> unchecked() const & {
709 if (Dims >= 0 && ndim() != Dims)
710 throw std::domain_error("array has incorrect number of dimensions: " + std::to_string(ndim()) +
711 "; expected " + std::to_string(Dims));
712 return detail::unchecked_reference<T, Dims>(data(), shape(), strides(), ndim());
713 }
715 /// Return a new view with all of the dimensions of length 1 removed
716 array squeeze() {
717 auto& api = detail::npy_api::get();
718 return reinterpret_steal<array>(api.PyArray_Squeeze_(m_ptr));
719 }
721 /// Resize array to given shape
722 /// If refcheck is true and more that one reference exist to this array
723 /// then resize will succeed only if it makes a reshape, i.e. original size doesn't change
724 void resize(ShapeContainer new_shape, bool refcheck = true) {
725 detail::npy_api::PyArray_Dims d = {
726 new_shape->data(), int(new_shape->size())
727 };
728 // try to resize, set ordering param to -1 cause it's not used anyway
729 object new_array = reinterpret_steal<object>(
730 detail::npy_api::get().PyArray_Resize_(m_ptr, &d, int(refcheck), -1)
731 );
732 if (!new_array) throw error_already_set();
733 if (isinstance<array>(new_array)) { *this = std::move(new_array); }
734 }
736 /// Ensure that the argument is a NumPy array
737 /// In case of an error, nullptr is returned and the Python error is cleared.
738 static array ensure(handle h, int ExtraFlags = 0) {
739 auto result = reinterpret_steal<array>(raw_array(h.ptr(), ExtraFlags));
740 if (!result)
741 PyErr_Clear();
742 return result;
743 }
745 protected:
746 template<typename, typename> friend struct detail::npy_format_descriptor;
748 void fail_dim_check(ssize_t dim, const std::string& msg) const {
749 throw index_error(msg + ": " + std::to_string(dim) +
750 " (ndim = " + std::to_string(ndim()) + ")");
751 }
753 template<typename... Ix> ssize_t byte_offset(Ix... index) const {
754 check_dimensions(index...);
755 return detail::byte_offset_unsafe(strides(), ssize_t(index)...);
756 }
758 void check_writeable() const {
759 if (!writeable())
760 throw std::domain_error("array is not writeable");
761 }
763 // Default, C-style strides
764 static std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
765 auto ndim = shape.size();
766 std::vector<ssize_t> strides(ndim, itemsize);
767 if (ndim > 0)
768 for (size_t i = ndim - 1; i > 0; --i)
769 strides[i - 1] = strides[i] * shape[i];
770 return strides;
771 }
773 // F-style strides; default when constructing an array_t with `ExtraFlags & f_style`
774 static std::vector<ssize_t> f_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
775 auto ndim = shape.size();
776 std::vector<ssize_t> strides(ndim, itemsize);
777 for (size_t i = 1; i < ndim; ++i)
778 strides[i] = strides[i - 1] * shape[i - 1];
779 return strides;
780 }
782 template<typename... Ix> void check_dimensions(Ix... index) const {
783 check_dimensions_impl(ssize_t(0), shape(), ssize_t(index)...);
784 }
786 void check_dimensions_impl(ssize_t, const ssize_t*) const { }
788 template<typename... Ix> void check_dimensions_impl(ssize_t axis, const ssize_t* shape, ssize_t i, Ix... index) const {
789 if (i >= *shape) {
790 throw index_error(std::string("index ") + std::to_string(i) +
791 " is out of bounds for axis " + std::to_string(axis) +
792 " with size " + std::to_string(*shape));
793 }
794 check_dimensions_impl(axis + 1, shape + 1, index...);
795 }
797 /// Create array from any object -- always returns a new reference
798 static PyObject *raw_array(PyObject *ptr, int ExtraFlags = 0) {
799 if (ptr == nullptr) {
800 PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array from a nullptr");
801 return nullptr;
802 }
803 return detail::npy_api::get().PyArray_FromAny_(
804 ptr, nullptr, 0, 0, detail::npy_api::NPY_ARRAY_ENSUREARRAY_ | ExtraFlags, nullptr);
805 }
806 };
808 template <typename T, int ExtraFlags = array::forcecast> class array_t : public array {
809 private:
810 struct private_ctor {};
811 // Delegating constructor needed when both moving and accessing in the same constructor
812 array_t(private_ctor, ShapeContainer &&shape, StridesContainer &&strides, const T *ptr, handle base)
813 : array(std::move(shape), std::move(strides), ptr, base) {}
814 public:
815 static_assert(!detail::array_info<T>::is_array, "Array types cannot be used with array_t");
817 using value_type = T;
819 array_t() : array(0, static_cast<const T *>(nullptr)) {}
820 array_t(handle h, borrowed_t) : array(h, borrowed_t{}) { }
821 array_t(handle h, stolen_t) : array(h, stolen_t{}) { }
823 PYBIND11_DEPRECATED("Use array_t<T>::ensure() instead")
824 array_t(handle h, bool is_borrowed) : array(raw_array_t(h.ptr()), stolen_t{}) {
825 if (!m_ptr) PyErr_Clear();
826 if (!is_borrowed) Py_XDECREF(h.ptr());
827 }
829 array_t(const object &o) : array(raw_array_t(o.ptr()), stolen_t{}) {
830 if (!m_ptr) throw error_already_set();
831 }
833 explicit array_t(const buffer_info& info) : array(info) { }
835 array_t(ShapeContainer shape, StridesContainer strides, const T *ptr = nullptr, handle base = handle())
836 : array(std::move(shape), std::move(strides), ptr, base) { }
838 explicit array_t(ShapeContainer shape, const T *ptr = nullptr, handle base = handle())
839 : array_t(private_ctor{}, std::move(shape),
840 ExtraFlags & f_style ? f_strides(*shape, itemsize()) : c_strides(*shape, itemsize()),
841 ptr, base) { }
843 explicit array_t(size_t count, const T *ptr = nullptr, handle base = handle())
844 : array({count}, {}, ptr, base) { }
846 constexpr ssize_t itemsize() const {
847 return sizeof(T);
848 }
850 template<typename... Ix> ssize_t index_at(Ix... index) const {
851 return offset_at(index...) / itemsize();
852 }
854 template<typename... Ix> const T* data(Ix... index) const {
855 return static_cast<const T*>(array::data(index...));
856 }
858 template<typename... Ix> T* mutable_data(Ix... index) {
859 return static_cast<T*>(array::mutable_data(index...));
860 }
862 // Reference to element at a given index
863 template<typename... Ix> const T& at(Ix... index) const {
864 if (sizeof...(index) != ndim())
865 fail_dim_check(sizeof...(index), "index dimension mismatch");
866 return *(static_cast<const T*>(array::data()) + byte_offset(ssize_t(index)...) / itemsize());
867 }
869 // Mutable reference to element at a given index
870 template<typename... Ix> T& mutable_at(Ix... index) {
871 if (sizeof...(index) != ndim())
872 fail_dim_check(sizeof...(index), "index dimension mismatch");
873 return *(static_cast<T*>(array::mutable_data()) + byte_offset(ssize_t(index)...) / itemsize());
874 }
876 /**
877 * Returns a proxy object that provides access to the array's data without bounds or
878 * dimensionality checking. Will throw if the array is missing the `writeable` flag. Use with
879 * care: the array must not be destroyed or reshaped for the duration of the returned object,
880 * and the caller must take care not to access invalid dimensions or dimension indices.
881 */
882 template <ssize_t Dims = -1> detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
883 return array::mutable_unchecked<T, Dims>();
884 }
886 /**
887 * Returns a proxy object that provides const access to the array's data without bounds or
888 * dimensionality checking. Unlike `unchecked()`, this does not require that the underlying
889 * array have the `writable` flag. Use with care: the array must not be destroyed or reshaped
890 * for the duration of the returned object, and the caller must take care not to access invalid
891 * dimensions or dimension indices.
892 */
893 template <ssize_t Dims = -1> detail::unchecked_reference<T, Dims> unchecked() const & {
894 return array::unchecked<T, Dims>();
895 }
897 /// Ensure that the argument is a NumPy array of the correct dtype (and if not, try to convert
898 /// it). In case of an error, nullptr is returned and the Python error is cleared.
899 static array_t ensure(handle h) {
900 auto result = reinterpret_steal<array_t>(raw_array_t(h.ptr()));
901 if (!result)
902 PyErr_Clear();
903 return result;
904 }
906 static bool check_(handle h) {
907 const auto &api = detail::npy_api::get();
908 return api.PyArray_Check_(h.ptr())
909 && api.PyArray_EquivTypes_(detail::array_proxy(h.ptr())->descr, dtype::of<T>().ptr());
910 }
912 protected:
913 /// Create array from any object -- always returns a new reference
914 static PyObject *raw_array_t(PyObject *ptr) {
915 if (ptr == nullptr) {
916 PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array_t from a nullptr");
917 return nullptr;
918 }
919 return detail::npy_api::get().PyArray_FromAny_(
920 ptr, dtype::of<T>().release().ptr(), 0, 0,
921 detail::npy_api::NPY_ARRAY_ENSUREARRAY_ | ExtraFlags, nullptr);
922 }
923 };
925 template <typename T>
926 struct format_descriptor<T, detail::enable_if_t<detail::is_pod_struct<T>::value>> {
927 static std::string format() {
928 return detail::npy_format_descriptor<typename std::remove_cv<T>::type>::format();
929 }
930 };
932 template <size_t N> struct format_descriptor<char[N]> {
933 static std::string format() { return std::to_string(N) + "s"; }
934 };
935 template <size_t N> struct format_descriptor<std::array<char, N>> {
936 static std::string format() { return std::to_string(N) + "s"; }
937 };
939 template <typename T>
940 struct format_descriptor<T, detail::enable_if_t<std::is_enum<T>::value>> {
941 static std::string format() {
942 return format_descriptor<
943 typename std::remove_cv<typename std::underlying_type<T>::type>::type>::format();
944 }
945 };
947 template <typename T>
948 struct format_descriptor<T, detail::enable_if_t<detail::array_info<T>::is_array>> {
949 static std::string format() {
950 using namespace detail;
951 PYBIND11_DESCR extents = _("(") + array_info<T>::extents() + _(")");
952 return extents.text() + format_descriptor<remove_all_extents_t<T>>::format();
953 }
954 };
956 NAMESPACE_BEGIN(detail)
957 template <typename T, int ExtraFlags>
958 struct pyobject_caster<array_t<T, ExtraFlags>> {
959 using type = array_t<T, ExtraFlags>;
961 bool load(handle src, bool convert) {
962 if (!convert && !type::check_(src))
963 return false;
964 value = type::ensure(src);
965 return static_cast<bool>(value);
966 }
968 static handle cast(const handle &src, return_value_policy /* policy */, handle /* parent */) {
969 return src.inc_ref();
970 }
971 PYBIND11_TYPE_CASTER(type, handle_type_name<type>::name());
972 };
974 template <typename T>
975 struct compare_buffer_info<T, detail::enable_if_t<detail::is_pod_struct<T>::value>> {
976 static bool compare(const buffer_info& b) {
977 return npy_api::get().PyArray_EquivTypes_(dtype::of<T>().ptr(), dtype(b).ptr());
978 }
979 };
981 template <typename T> struct npy_format_descriptor<T, enable_if_t<satisfies_any_of<T, std::is_arithmetic, is_complex>::value>> {
982 private:
983 // NB: the order here must match the one in common.h
984 constexpr static const int values[15] = {
985 npy_api::NPY_BOOL_,
986 npy_api::NPY_BYTE_, npy_api::NPY_UBYTE_, npy_api::NPY_SHORT_, npy_api::NPY_USHORT_,
987 npy_api::NPY_INT_, npy_api::NPY_UINT_, npy_api::NPY_LONGLONG_, npy_api::NPY_ULONGLONG_,
988 npy_api::NPY_FLOAT_, npy_api::NPY_DOUBLE_, npy_api::NPY_LONGDOUBLE_,
989 npy_api::NPY_CFLOAT_, npy_api::NPY_CDOUBLE_, npy_api::NPY_CLONGDOUBLE_
990 };
992 public:
993 static constexpr int value = values[detail::is_fmt_numeric<T>::index];
995 static pybind11::dtype dtype() {
996 if (auto ptr = npy_api::get().PyArray_DescrFromType_(value))
997 return reinterpret_borrow<pybind11::dtype>(ptr);
998 pybind11_fail("Unsupported buffer format!");
999 }
1000 template <typename T2 = T, enable_if_t<std::is_integral<T2>::value, int> = 0>
1001 static PYBIND11_DESCR name() {
1002 return _<std::is_same<T, bool>::value>(_("bool"),
1003 _<std::is_signed<T>::value>("int", "uint") + _<sizeof(T)*8>());
1004 }
1005 template <typename T2 = T, enable_if_t<std::is_floating_point<T2>::value, int> = 0>
1006 static PYBIND11_DESCR name() {
1007 return _<std::is_same<T, float>::value || std::is_same<T, double>::value>(
1008 _("float") + _<sizeof(T)*8>(), _("longdouble"));
1009 }
1010 template <typename T2 = T, enable_if_t<is_complex<T2>::value, int> = 0>
1011 static PYBIND11_DESCR name() {
1012 return _<std::is_same<typename T2::value_type, float>::value || std::is_same<typename T2::value_type, double>::value>(
1013 _("complex") + _<sizeof(typename T2::value_type)*16>(), _("longcomplex"));
1014 }
1015 };
1017 #define PYBIND11_DECL_CHAR_FMT \
1018 static PYBIND11_DESCR name() { return _("S") + _<N>(); } \
1019 static pybind11::dtype dtype() { return pybind11::dtype(std::string("S") + std::to_string(N)); }
1020 template <size_t N> struct npy_format_descriptor<char[N]> { PYBIND11_DECL_CHAR_FMT };
1021 template <size_t N> struct npy_format_descriptor<std::array<char, N>> { PYBIND11_DECL_CHAR_FMT };
1022 #undef PYBIND11_DECL_CHAR_FMT
1024 template<typename T> struct npy_format_descriptor<T, enable_if_t<array_info<T>::is_array>> {
1025 private:
1026 using base_descr = npy_format_descriptor<typename array_info<T>::type>;
1027 public:
1028 static_assert(!array_info<T>::is_empty, "Zero-sized arrays are not supported");
1030 static PYBIND11_DESCR name() { return _("(") + array_info<T>::extents() + _(")") + base_descr::name(); }
1031 static pybind11::dtype dtype() {
1032 list shape;
1033 array_info<T>::append_extents(shape);
1034 return pybind11::dtype::from_args(pybind11::make_tuple(base_descr::dtype(), shape));
1035 }
1036 };
1038 template<typename T> struct npy_format_descriptor<T, enable_if_t<std::is_enum<T>::value>> {
1039 private:
1040 using base_descr = npy_format_descriptor<typename std::underlying_type<T>::type>;
1041 public:
1042 static PYBIND11_DESCR name() { return base_descr::name(); }
1043 static pybind11::dtype dtype() { return base_descr::dtype(); }
1044 };
1046 struct field_descriptor {
1047 const char *name;
1048 ssize_t offset;
1049 ssize_t size;
1050 std::string format;
1051 dtype descr;
1052 };
1054 inline PYBIND11_NOINLINE void register_structured_dtype(
1055 const std::initializer_list<field_descriptor>& fields,
1056 const std::type_info& tinfo, ssize_t itemsize,
1057 bool (*direct_converter)(PyObject *, void *&)) {
1059 auto& numpy_internals = get_numpy_internals();
1060 if (numpy_internals.get_type_info(tinfo, false))
1061 pybind11_fail("NumPy: dtype is already registered");
1063 list names, formats, offsets;
1064 for (auto field : fields) {
1065 if (!field.descr)
1066 pybind11_fail(std::string("NumPy: unsupported field dtype: `") +
1067 field.name + "` @ " + tinfo.name());
1068 names.append(PYBIND11_STR_TYPE(field.name));
1069 formats.append(field.descr);
1070 offsets.append(pybind11::int_(field.offset));
1071 }
1072 auto dtype_ptr = pybind11::dtype(names, formats, offsets, itemsize).release().ptr();
1074 // There is an existing bug in NumPy (as of v1.11): trailing bytes are
1075 // not encoded explicitly into the format string. This will supposedly
1076 // get fixed in v1.12; for further details, see these:
1077 // - https://github.com/numpy/numpy/issues/7797
1078 // - https://github.com/numpy/numpy/pull/7798
1079 // Because of this, we won't use numpy's logic to generate buffer format
1080 // strings and will just do it ourselves.
1081 std::vector<field_descriptor> ordered_fields(fields);
1082 std::sort(ordered_fields.begin(), ordered_fields.end(),
1083 [](const field_descriptor &a, const field_descriptor &b) { return a.offset < b.offset; });
1084 ssize_t offset = 0;
1085 std::ostringstream oss;
1086 // mark the structure as unaligned with '^', because numpy and C++ don't
1087 // always agree about alignment (particularly for complex), and we're
1088 // explicitly listing all our padding. This depends on none of the fields
1089 // overriding the endianness. Putting the ^ in front of individual fields
1090 // isn't guaranteed to work due to https://github.com/numpy/numpy/issues/9049
1091 oss << "^T{";
1092 for (auto& field : ordered_fields) {
1093 if (field.offset > offset)
1094 oss << (field.offset - offset) << 'x';
1095 oss << field.format << ':' << field.name << ':';
1096 offset = field.offset + field.size;
1097 }
1098 if (itemsize > offset)
1099 oss << (itemsize - offset) << 'x';
1100 oss << '}';
1101 auto format_str = oss.str();
1103 // Sanity check: verify that NumPy properly parses our buffer format string
1104 auto& api = npy_api::get();
1105 auto arr = array(buffer_info(nullptr, itemsize, format_str, 1));
1106 if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr()))
1107 pybind11_fail("NumPy: invalid buffer descriptor!");
1109 auto tindex = std::type_index(tinfo);
1110 numpy_internals.registered_dtypes[tindex] = { dtype_ptr, format_str };
1111 get_internals().direct_conversions[tindex].push_back(direct_converter);
1112 }
1114 template <typename T, typename SFINAE> struct npy_format_descriptor {
1115 static_assert(is_pod_struct<T>::value, "Attempt to use a non-POD or unimplemented POD type as a numpy dtype");
1117 static PYBIND11_DESCR name() { return make_caster<T>::name(); }
1119 static pybind11::dtype dtype() {
1120 return reinterpret_borrow<pybind11::dtype>(dtype_ptr());
1121 }
1123 static std::string format() {
1124 static auto format_str = get_numpy_internals().get_type_info<T>(true)->format_str;
1125 return format_str;
1126 }
1128 static void register_dtype(const std::initializer_list<field_descriptor>& fields) {
1129 register_structured_dtype(fields, typeid(typename std::remove_cv<T>::type),
1130 sizeof(T), &direct_converter);
1131 }
1133 private:
1134 static PyObject* dtype_ptr() {
1135 static PyObject* ptr = get_numpy_internals().get_type_info<T>(true)->dtype_ptr;
1136 return ptr;
1137 }
1139 static bool direct_converter(PyObject *obj, void*& value) {
1140 auto& api = npy_api::get();
1141 if (!PyObject_TypeCheck(obj, api.PyVoidArrType_Type_))
1142 return false;
1143 if (auto descr = reinterpret_steal<object>(api.PyArray_DescrFromScalar_(obj))) {
1144 if (api.PyArray_EquivTypes_(dtype_ptr(), descr.ptr())) {
1145 value = ((PyVoidScalarObject_Proxy *) obj)->obval;
1146 return true;
1147 }
1148 }
1149 return false;
1150 }
1151 };
1153 #ifdef __CLION_IDE__ // replace heavy macro with dummy code for the IDE (doesn't affect code)
1154 # define PYBIND11_NUMPY_DTYPE(Type, ...) ((void)0)
1155 # define PYBIND11_NUMPY_DTYPE_EX(Type, ...) ((void)0)
1156 #else
1158 #define PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, Name) \
1159 ::pybind11::detail::field_descriptor { \
1160 Name, offsetof(T, Field), sizeof(decltype(std::declval<T>().Field)), \
1161 ::pybind11::format_descriptor<decltype(std::declval<T>().Field)>::format(), \
1162 ::pybind11::detail::npy_format_descriptor<decltype(std::declval<T>().Field)>::dtype() \
1163 }
1165 // Extract name, offset and format descriptor for a struct field
1166 #define PYBIND11_FIELD_DESCRIPTOR(T, Field) PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, #Field)
1168 // The main idea of this macro is borrowed from https://github.com/swansontec/map-macro
1169 // (C) William Swanson, Paul Fultz
1170 #define PYBIND11_EVAL0(...) __VA_ARGS__
1171 #define PYBIND11_EVAL1(...) PYBIND11_EVAL0 (PYBIND11_EVAL0 (PYBIND11_EVAL0 (__VA_ARGS__)))
1172 #define PYBIND11_EVAL2(...) PYBIND11_EVAL1 (PYBIND11_EVAL1 (PYBIND11_EVAL1 (__VA_ARGS__)))
1173 #define PYBIND11_EVAL3(...) PYBIND11_EVAL2 (PYBIND11_EVAL2 (PYBIND11_EVAL2 (__VA_ARGS__)))
1174 #define PYBIND11_EVAL4(...) PYBIND11_EVAL3 (PYBIND11_EVAL3 (PYBIND11_EVAL3 (__VA_ARGS__)))
1175 #define PYBIND11_EVAL(...) PYBIND11_EVAL4 (PYBIND11_EVAL4 (PYBIND11_EVAL4 (__VA_ARGS__)))
1176 #define PYBIND11_MAP_END(...)
1177 #define PYBIND11_MAP_OUT
1178 #define PYBIND11_MAP_COMMA ,
1179 #define PYBIND11_MAP_GET_END() 0, PYBIND11_MAP_END
1180 #define PYBIND11_MAP_NEXT0(test, next, ...) next PYBIND11_MAP_OUT
1181 #define PYBIND11_MAP_NEXT1(test, next) PYBIND11_MAP_NEXT0 (test, next, 0)
1182 #define PYBIND11_MAP_NEXT(test, next) PYBIND11_MAP_NEXT1 (PYBIND11_MAP_GET_END test, next)
1183 #ifdef _MSC_VER // MSVC is not as eager to expand macros, hence this workaround
1184 #define PYBIND11_MAP_LIST_NEXT1(test, next) \
1185 PYBIND11_EVAL0 (PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0))
1186 #else
1187 #define PYBIND11_MAP_LIST_NEXT1(test, next) \
1188 PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0)
1189 #endif
1190 #define PYBIND11_MAP_LIST_NEXT(test, next) \
1191 PYBIND11_MAP_LIST_NEXT1 (PYBIND11_MAP_GET_END test, next)
1192 #define PYBIND11_MAP_LIST0(f, t, x, peek, ...) \
1193 f(t, x) PYBIND11_MAP_LIST_NEXT (peek, PYBIND11_MAP_LIST1) (f, t, peek, __VA_ARGS__)
1194 #define PYBIND11_MAP_LIST1(f, t, x, peek, ...) \
1195 f(t, x) PYBIND11_MAP_LIST_NEXT (peek, PYBIND11_MAP_LIST0) (f, t, peek, __VA_ARGS__)
1196 // PYBIND11_MAP_LIST(f, t, a1, a2, ...) expands to f(t, a1), f(t, a2), ...
1197 #define PYBIND11_MAP_LIST(f, t, ...) \
1198 PYBIND11_EVAL (PYBIND11_MAP_LIST1 (f, t, __VA_ARGS__, (), 0))
1200 #define PYBIND11_NUMPY_DTYPE(Type, ...) \
1201 ::pybind11::detail::npy_format_descriptor<Type>::register_dtype \
1202 ({PYBIND11_MAP_LIST (PYBIND11_FIELD_DESCRIPTOR, Type, __VA_ARGS__)})
1204 #ifdef _MSC_VER
1205 #define PYBIND11_MAP2_LIST_NEXT1(test, next) \
1206 PYBIND11_EVAL0 (PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0))
1207 #else
1208 #define PYBIND11_MAP2_LIST_NEXT1(test, next) \
1209 PYBIND11_MAP_NEXT0 (test, PYBIND11_MAP_COMMA next, 0)
1210 #endif
1211 #define PYBIND11_MAP2_LIST_NEXT(test, next) \
1212 PYBIND11_MAP2_LIST_NEXT1 (PYBIND11_MAP_GET_END test, next)
1213 #define PYBIND11_MAP2_LIST0(f, t, x1, x2, peek, ...) \
1214 f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT (peek, PYBIND11_MAP2_LIST1) (f, t, peek, __VA_ARGS__)
1215 #define PYBIND11_MAP2_LIST1(f, t, x1, x2, peek, ...) \
1216 f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT (peek, PYBIND11_MAP2_LIST0) (f, t, peek, __VA_ARGS__)
1217 // PYBIND11_MAP2_LIST(f, t, a1, a2, ...) expands to f(t, a1, a2), f(t, a3, a4), ...
1218 #define PYBIND11_MAP2_LIST(f, t, ...) \
1219 PYBIND11_EVAL (PYBIND11_MAP2_LIST1 (f, t, __VA_ARGS__, (), 0))
1221 #define PYBIND11_NUMPY_DTYPE_EX(Type, ...) \
1222 ::pybind11::detail::npy_format_descriptor<Type>::register_dtype \
1223 ({PYBIND11_MAP2_LIST (PYBIND11_FIELD_DESCRIPTOR_EX, Type, __VA_ARGS__)})
1225 #endif // __CLION_IDE__
1227 template <class T>
1228 using array_iterator = typename std::add_pointer<T>::type;
1230 template <class T>
1231 array_iterator<T> array_begin(const buffer_info& buffer) {
1232 return array_iterator<T>(reinterpret_cast<T*>(buffer.ptr));
1233 }
1235 template <class T>
1236 array_iterator<T> array_end(const buffer_info& buffer) {
1237 return array_iterator<T>(reinterpret_cast<T*>(buffer.ptr) + buffer.size);
1238 }
1240 class common_iterator {
1241 public:
1242 using container_type = std::vector<ssize_t>;
1243 using value_type = container_type::value_type;
1244 using size_type = container_type::size_type;
1246 common_iterator() : p_ptr(0), m_strides() {}
1248 common_iterator(void* ptr, const container_type& strides, const container_type& shape)
1249 : p_ptr(reinterpret_cast<char*>(ptr)), m_strides(strides.size()) {
1250 m_strides.back() = static_cast<value_type>(strides.back());
1251 for (size_type i = m_strides.size() - 1; i != 0; --i) {
1252 size_type j = i - 1;
1253 value_type s = static_cast<value_type>(shape[i]);
1254 m_strides[j] = strides[j] + m_strides[i] - strides[i] * s;
1255 }
1256 }
1258 void increment(size_type dim) {
1259 p_ptr += m_strides[dim];
1260 }
1262 void* data() const {
1263 return p_ptr;
1264 }
1266 private:
1267 char* p_ptr;
1268 container_type m_strides;
1269 };
1271 template <size_t N> class multi_array_iterator {
1272 public:
1273 using container_type = std::vector<ssize_t>;
1275 multi_array_iterator(const std::array<buffer_info, N> &buffers,
1276 const container_type &shape)
1277 : m_shape(shape.size()), m_index(shape.size(), 0),
1278 m_common_iterator() {
1280 // Manual copy to avoid conversion warning if using std::copy
1281 for (size_t i = 0; i < shape.size(); ++i)
1282 m_shape[i] = shape[i];
1284 container_type strides(shape.size());
1285 for (size_t i = 0; i < N; ++i)
1286 init_common_iterator(buffers[i], shape, m_common_iterator[i], strides);
1287 }
1289 multi_array_iterator& operator++() {
1290 for (size_t j = m_index.size(); j != 0; --j) {
1291 size_t i = j - 1;
1292 if (++m_index[i] != m_shape[i]) {
1293 increment_common_iterator(i);
1294 break;
1295 } else {
1296 m_index[i] = 0;
1297 }
1298 }
1299 return *this;
1300 }
1302 template <size_t K, class T = void> T* data() const {
1303 return reinterpret_cast<T*>(m_common_iterator[K].data());
1304 }
1306 private:
1308 using common_iter = common_iterator;
1310 void init_common_iterator(const buffer_info &buffer,
1311 const container_type &shape,
1312 common_iter &iterator,
1313 container_type &strides) {
1314 auto buffer_shape_iter = buffer.shape.rbegin();
1315 auto buffer_strides_iter = buffer.strides.rbegin();
1316 auto shape_iter = shape.rbegin();
1317 auto strides_iter = strides.rbegin();
1319 while (buffer_shape_iter != buffer.shape.rend()) {
1320 if (*shape_iter == *buffer_shape_iter)
1321 *strides_iter = *buffer_strides_iter;
1322 else
1323 *strides_iter = 0;
1325 ++buffer_shape_iter;
1326 ++buffer_strides_iter;
1327 ++shape_iter;
1328 ++strides_iter;
1329 }
1331 std::fill(strides_iter, strides.rend(), 0);
1332 iterator = common_iter(buffer.ptr, strides, shape);
1333 }
1335 void increment_common_iterator(size_t dim) {
1336 for (auto &iter : m_common_iterator)
1337 iter.increment(dim);
1338 }
1340 container_type m_shape;
1341 container_type m_index;
1342 std::array<common_iter, N> m_common_iterator;
1343 };
1345 enum class broadcast_trivial { non_trivial, c_trivial, f_trivial };
1347 // Populates the shape and number of dimensions for the set of buffers. Returns a broadcast_trivial
1348 // enum value indicating whether the broadcast is "trivial"--that is, has each buffer being either a
1349 // singleton or a full-size, C-contiguous (`c_trivial`) or Fortran-contiguous (`f_trivial`) storage
1350 // buffer; returns `non_trivial` otherwise.
1351 template <size_t N>
1352 broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &ndim, std::vector<ssize_t> &shape) {
1353 ndim = std::accumulate(buffers.begin(), buffers.end(), ssize_t(0), [](ssize_t res, const buffer_info &buf) {
1354 return std::max(res, buf.ndim);
1355 });
1357 shape.clear();
1358 shape.resize((size_t) ndim, 1);
1360 // Figure out the output size, and make sure all input arrays conform (i.e. are either size 1 or
1361 // the full size).
1362 for (size_t i = 0; i < N; ++i) {
1363 auto res_iter = shape.rbegin();
1364 auto end = buffers[i].shape.rend();
1365 for (auto shape_iter = buffers[i].shape.rbegin(); shape_iter != end; ++shape_iter, ++res_iter) {
1366 const auto &dim_size_in = *shape_iter;
1367 auto &dim_size_out = *res_iter;
1369 // Each input dimension can either be 1 or `n`, but `n` values must match across buffers
1370 if (dim_size_out == 1)
1371 dim_size_out = dim_size_in;
1372 else if (dim_size_in != 1 && dim_size_in != dim_size_out)
1373 pybind11_fail("pybind11::vectorize: incompatible size/dimension of inputs!");
1374 }
1375 }
1377 bool trivial_broadcast_c = true;
1378 bool trivial_broadcast_f = true;
1379 for (size_t i = 0; i < N && (trivial_broadcast_c || trivial_broadcast_f); ++i) {
1380 if (buffers[i].size == 1)
1381 continue;
1383 // Require the same number of dimensions:
1384 if (buffers[i].ndim != ndim)
1385 return broadcast_trivial::non_trivial;
1387 // Require all dimensions be full-size:
1388 if (!std::equal(buffers[i].shape.cbegin(), buffers[i].shape.cend(), shape.cbegin()))
1389 return broadcast_trivial::non_trivial;
1391 // Check for C contiguity (but only if previous inputs were also C contiguous)
1392 if (trivial_broadcast_c) {
1393 ssize_t expect_stride = buffers[i].itemsize;
1394 auto end = buffers[i].shape.crend();
1395 for (auto shape_iter = buffers[i].shape.crbegin(), stride_iter = buffers[i].strides.crbegin();
1396 trivial_broadcast_c && shape_iter != end; ++shape_iter, ++stride_iter) {
1397 if (expect_stride == *stride_iter)
1398 expect_stride *= *shape_iter;
1399 else
1400 trivial_broadcast_c = false;
1401 }
1402 }
1404 // Check for Fortran contiguity (if previous inputs were also F contiguous)
1405 if (trivial_broadcast_f) {
1406 ssize_t expect_stride = buffers[i].itemsize;
1407 auto end = buffers[i].shape.cend();
1408 for (auto shape_iter = buffers[i].shape.cbegin(), stride_iter = buffers[i].strides.cbegin();
1409 trivial_broadcast_f && shape_iter != end; ++shape_iter, ++stride_iter) {
1410 if (expect_stride == *stride_iter)
1411 expect_stride *= *shape_iter;
1412 else
1413 trivial_broadcast_f = false;
1414 }
1415 }
1416 }
1418 return
1419 trivial_broadcast_c ? broadcast_trivial::c_trivial :
1420 trivial_broadcast_f ? broadcast_trivial::f_trivial :
1421 broadcast_trivial::non_trivial;
1422 }
1424 template <typename T>
1425 struct vectorize_arg {
1426 static_assert(!std::is_rvalue_reference<T>::value, "Functions with rvalue reference arguments cannot be vectorized");
1427 // The wrapped function gets called with this type:
1428 using call_type = remove_reference_t<T>;
1429 // Is this a vectorized argument?
1430 static constexpr bool vectorize =
1431 satisfies_any_of<call_type, std::is_arithmetic, is_complex, std::is_pod>::value &&
1432 satisfies_none_of<call_type, std::is_pointer, std::is_array, is_std_array, std::is_enum>::value &&
1433 (!std::is_reference<T>::value ||
1434 (std::is_lvalue_reference<T>::value && std::is_const<call_type>::value));
1435 // Accept this type: an array for vectorized types, otherwise the type as-is:
1436 using type = conditional_t<vectorize, array_t<remove_cv_t<call_type>, array::forcecast>, T>;
1437 };
1439 template <typename Func, typename Return, typename... Args>
1440 struct vectorize_helper {
1441 private:
1442 static constexpr size_t N = sizeof...(Args);
1443 static constexpr size_t NVectorized = constexpr_sum(vectorize_arg<Args>::vectorize...);
1444 static_assert(NVectorized >= 1,
1445 "pybind11::vectorize(...) requires a function with at least one vectorizable argument");
1447 public:
1448 template <typename T>
1449 explicit vectorize_helper(T &&f) : f(std::forward<T>(f)) { }
1451 object operator()(typename vectorize_arg<Args>::type... args) {
1452 return run(args...,
1453 make_index_sequence<N>(),
1454 select_indices<vectorize_arg<Args>::vectorize...>(),
1455 make_index_sequence<NVectorized>());
1456 }
1458 private:
1459 remove_reference_t<Func> f;
1461 template <size_t Index> using param_n_t = typename pack_element<Index, typename vectorize_arg<Args>::call_type...>::type;
1463 // Runs a vectorized function given arguments tuple and three index sequences:
1464 // - Index is the full set of 0 ... (N-1) argument indices;
1465 // - VIndex is the subset of argument indices with vectorized parameters, letting us access
1466 // vectorized arguments (anything not in this sequence is passed through)
1467 // - BIndex is a incremental sequence (beginning at 0) of the same size as VIndex, so that
1468 // we can store vectorized buffer_infos in an array (argument VIndex has its buffer at
1469 // index BIndex in the array).
1470 template <size_t... Index, size_t... VIndex, size_t... BIndex> object run(
1471 typename vectorize_arg<Args>::type &...args,
1472 index_sequence<Index...> i_seq, index_sequence<VIndex...> vi_seq, index_sequence<BIndex...> bi_seq) {
1474 // Pointers to values the function was called with; the vectorized ones set here will start
1475 // out as array_t<T> pointers, but they will be changed them to T pointers before we make
1476 // call the wrapped function. Non-vectorized pointers are left as-is.
1477 std::array<void *, N> params{{ &args... }};
1479 // The array of `buffer_info`s of vectorized arguments:
1480 std::array<buffer_info, NVectorized> buffers{{ reinterpret_cast<array *>(params[VIndex])->request()... }};
1482 /* Determine dimensions parameters of output array */
1483 ssize_t nd = 0;
1484 std::vector<ssize_t> shape(0);
1485 auto trivial = broadcast(buffers, nd, shape);
1486 size_t ndim = (size_t) nd;
1488 size_t size = std::accumulate(shape.begin(), shape.end(), (size_t) 1, std::multiplies<size_t>());
1490 // If all arguments are 0-dimension arrays (i.e. single values) return a plain value (i.e.
1491 // not wrapped in an array).
1492 if (size == 1 && ndim == 0) {
1493 PYBIND11_EXPAND_SIDE_EFFECTS(params[VIndex] = buffers[BIndex].ptr);
1494 return cast(f(*reinterpret_cast<param_n_t<Index> *>(params[Index])...));
1495 }
1497 array_t<Return> result;
1498 if (trivial == broadcast_trivial::f_trivial) result = array_t<Return, array::f_style>(shape);
1499 else result = array_t<Return>(shape);
1501 if (size == 0) return result;
1503 /* Call the function */
1504 if (trivial == broadcast_trivial::non_trivial)
1505 apply_broadcast(buffers, params, result, i_seq, vi_seq, bi_seq);
1506 else
1507 apply_trivial(buffers, params, result.mutable_data(), size, i_seq, vi_seq, bi_seq);
1509 return result;
1510 }
1512 template <size_t... Index, size_t... VIndex, size_t... BIndex>
1513 void apply_trivial(std::array<buffer_info, NVectorized> &buffers,
1514 std::array<void *, N> ¶ms,
1515 Return *out,
1516 size_t size,
1517 index_sequence<Index...>, index_sequence<VIndex...>, index_sequence<BIndex...>) {
1519 // Initialize an array of mutable byte references and sizes with references set to the
1520 // appropriate pointer in `params`; as we iterate, we'll increment each pointer by its size
1521 // (except for singletons, which get an increment of 0).
1522 std::array<std::pair<unsigned char *&, const size_t>, NVectorized> vecparams{{
1523 std::pair<unsigned char *&, const size_t>(
1524 reinterpret_cast<unsigned char *&>(params[VIndex] = buffers[BIndex].ptr),
1525 buffers[BIndex].size == 1 ? 0 : sizeof(param_n_t<VIndex>)
1526 )...
1527 }};
1529 for (size_t i = 0; i < size; ++i) {
1530 out[i] = f(*reinterpret_cast<param_n_t<Index> *>(params[Index])...);
1531 for (auto &x : vecparams) x.first += x.second;
1532 }
1533 }
1535 template <size_t... Index, size_t... VIndex, size_t... BIndex>
1536 void apply_broadcast(std::array<buffer_info, NVectorized> &buffers,
1537 std::array<void *, N> ¶ms,
1538 array_t<Return> &output_array,
1539 index_sequence<Index...>, index_sequence<VIndex...>, index_sequence<BIndex...>) {
1541 buffer_info output = output_array.request();
1542 multi_array_iterator<NVectorized> input_iter(buffers, output.shape);
1544 for (array_iterator<Return> iter = array_begin<Return>(output), end = array_end<Return>(output);
1545 iter != end;
1546 ++iter, ++input_iter) {
1547 PYBIND11_EXPAND_SIDE_EFFECTS((
1548 params[VIndex] = input_iter.template data<BIndex>()
1549 ));
1550 *iter = f(*reinterpret_cast<param_n_t<Index> *>(std::get<Index>(params))...);
1551 }
1552 }
1553 };
1555 template <typename Func, typename Return, typename... Args>
1556 vectorize_helper<Func, Return, Args...>
1557 vectorize_extractor(const Func &f, Return (*) (Args ...)) {
1558 return detail::vectorize_helper<Func, Return, Args...>(f);
1559 }
1561 template <typename T, int Flags> struct handle_type_name<array_t<T, Flags>> {
1562 static PYBIND11_DESCR name() {
1563 return _("numpy.ndarray[") + npy_format_descriptor<T>::name() + _("]");
1564 }
1565 };
1567 NAMESPACE_END(detail)
1569 // Vanilla pointer vectorizer:
1570 template <typename Return, typename... Args>
1571 detail::vectorize_helper<Return (*)(Args...), Return, Args...>
1572 vectorize(Return (*f) (Args ...)) {
1573 return detail::vectorize_helper<Return (*)(Args...), Return, Args...>(f);
1574 }
1576 // lambda vectorizer:
1577 template <typename Func, detail::enable_if_t<detail::is_lambda<Func>::value, int> = 0>
1578 auto vectorize(Func &&f) -> decltype(
1579 detail::vectorize_extractor(std::forward<Func>(f), (detail::function_signature_t<Func> *) nullptr)) {
1580 return detail::vectorize_extractor(std::forward<Func>(f), (detail::function_signature_t<Func> *) nullptr);
1581 }
1583 // Vectorize a class method (non-const):
1584 template <typename Return, typename Class, typename... Args,
1585 typename Helper = detail::vectorize_helper<decltype(std::mem_fn(std::declval<Return (Class::*)(Args...)>())), Return, Class *, Args...>>
1586 Helper vectorize(Return (Class::*f)(Args...)) {
1587 return Helper(std::mem_fn(f));
1588 }
1590 // Vectorize a class method (const):
1591 template <typename Return, typename Class, typename... Args,
1592 typename Helper = detail::vectorize_helper<decltype(std::mem_fn(std::declval<Return (Class::*)(Args...) const>())), Return, const Class *, Args...>>
1593 Helper vectorize(Return (Class::*f)(Args...) const) {
1594 return Helper(std::mem_fn(f));
1595 }
1597 NAMESPACE_END(PYBIND11_NAMESPACE)
1599 #if defined(_MSC_VER)
1600 #pragma warning(pop)
1601 #endif