ext/pybind11/tests/test_numpy_dtypes.cpp - testing/jenkins-gem5-prod - Git at Google

 /*
   tests/test_numpy_dtypes.cpp -- Structured and compound NumPy dtypes

   Copyright (c) 2016 Ivan Smirnov

   All rights reserved. Use of this source code is governed by a
   BSD-style license that can be found in the LICENSE file.
 */

 #include "pybind11_tests.h"
 #include <pybind11/numpy.h>

 #ifdef __GNUC__
 #define PYBIND11_PACKED(cls) cls __attribute__((__packed__))
 #else
 #define PYBIND11_PACKED(cls) __pragma(pack(push, 1)) cls __pragma(pack(pop))
 #endif

 namespace py = pybind11;

 struct SimpleStruct {
     bool bool_;
     uint32_t uint_;
     float float_;
     long double ldbl_;
 };

 std::ostream& operator<<(std::ostream& os, const SimpleStruct& v) {
     return os << "s:" << v.bool_ << "," << v.uint_ << "," << v.float_ << "," << v.ldbl_;
 }

 PYBIND11_PACKED(struct PackedStruct {
     bool bool_;
     uint32_t uint_;
     float float_;
     long double ldbl_;
 });

 std::ostream& operator<<(std::ostream& os, const PackedStruct& v) {
     return os << "p:" << v.bool_ << "," << v.uint_ << "," << v.float_ << "," << v.ldbl_;
 }

 PYBIND11_PACKED(struct NestedStruct {
     SimpleStruct a;
     PackedStruct b;
 });

 std::ostream& operator<<(std::ostream& os, const NestedStruct& v) {
     return os << "n:a=" << v.a << ";b=" << v.b;
 }

 struct PartialStruct {
     bool bool_;
     uint32_t uint_;
     float float_;
     uint64_t dummy2;
     long double ldbl_;
 };

 struct PartialNestedStruct {
     uint64_t dummy1;
     PartialStruct a;
     uint64_t dummy2;
 };

 struct UnboundStruct { };

 struct StringStruct {
     char a[3];
     std::array<char, 3> b;
 };

 struct ComplexStruct {
     std::complex<float> cflt;
     std::complex<double> cdbl;
 };

 std::ostream& operator<<(std::ostream& os, const ComplexStruct& v) {
     return os << "c:" << v.cflt << "," << v.cdbl;
 }

 struct ArrayStruct {
     char a[3][4];
     int32_t b[2];
     std::array<uint8_t, 3> c;
     std::array<float, 2> d[4];
 };

 PYBIND11_PACKED(struct StructWithUglyNames {
     int8_t __x__;
     uint64_t __y__;
 });

 enum class E1 : int64_t { A = -1, B = 1 };
 enum E2 : uint8_t { X = 1, Y = 2 };

 PYBIND11_PACKED(struct EnumStruct {
     E1 e1;
     E2 e2;
 });

 std::ostream& operator<<(std::ostream& os, const StringStruct& v) {
     os << "a='";
     for (size_t i = 0; i < 3 && v.a[i]; i++) os << v.a[i];
     os << "',b='";
     for (size_t i = 0; i < 3 && v.b[i]; i++) os << v.b[i];
     return os << "'";
 }

 std::ostream& operator<<(std::ostream& os, const ArrayStruct& v) {
     os << "a={";
     for (int i = 0; i < 3; i++) {
         if (i > 0)
             os << ',';
         os << '{';
         for (int j = 0; j < 3; j++)
             os << v.a[i][j] << ',';
         os << v.a[i][3] << '}';
     }
     os << "},b={" << v.b[0] << ',' << v.b[1];
     os << "},c={" << int(v.c[0]) << ',' << int(v.c[1]) << ',' << int(v.c[2]);
     os << "},d={";
     for (int i = 0; i < 4; i++) {
         if (i > 0)
             os << ',';
         os << '{' << v.d[i][0] << ',' << v.d[i][1] << '}';
     }
     return os << '}';
 }

 std::ostream& operator<<(std::ostream& os, const EnumStruct& v) {
     return os << "e1=" << (v.e1 == E1::A ? "A" : "B") << ",e2=" << (v.e2 == E2::X ? "X" : "Y");
 }

 template <typename T>
 py::array mkarray_via_buffer(size_t n) {
     return py::array(py::buffer_info(nullptr, sizeof(T),
                                      py::format_descriptor<T>::format(),
                                      1, { n }, { sizeof(T) }));
 }

 #define SET_TEST_VALS(s, i) do { \
     s.bool_ = (i) % 2 != 0; \
     s.uint_ = (uint32_t) (i); \
     s.float_ = (float) (i) * 1.5f; \
     s.ldbl_ = (long double) (i) * -2.5L; } while (0)

 template <typename S>
 py::array_t<S, 0> create_recarray(size_t n) {
     auto arr = mkarray_via_buffer<S>(n);
     auto req = arr.request();
     auto ptr = static_cast<S*>(req.ptr);
     for (size_t i = 0; i < n; i++) {
         SET_TEST_VALS(ptr[i], i);
     }
     return arr;
 }

 template <typename S>
 py::list print_recarray(py::array_t<S, 0> arr) {
     const auto req = arr.request();
     const auto ptr = static_cast<S*>(req.ptr);
     auto l = py::list();
     for (ssize_t i = 0; i < req.size; i++) {
         std::stringstream ss;
         ss << ptr[i];
         l.append(py::str(ss.str()));
     }
     return l;
 }

 py::array_t<int32_t, 0> test_array_ctors(int i) {
     using arr_t = py::array_t<int32_t, 0>;

     std::vector<int32_t> data { 1, 2, 3, 4, 5, 6 };
     std::vector<ssize_t> shape { 3, 2 };
     std::vector<ssize_t> strides { 8, 4 };

     auto ptr = data.data();
     auto vptr = (void *) ptr;
     auto dtype = py::dtype("int32");

     py::buffer_info buf_ndim1(vptr, 4, "i", 6);
     py::buffer_info buf_ndim1_null(nullptr, 4, "i", 6);
     py::buffer_info buf_ndim2(vptr, 4, "i", 2, shape, strides);
     py::buffer_info buf_ndim2_null(nullptr, 4, "i", 2, shape, strides);

     auto fill = [](py::array arr) {
         auto req = arr.request();
         for (int i = 0; i < 6; i++) ((int32_t *) req.ptr)[i] = i + 1;
         return arr;
     };

     switch (i) {
     // shape: (3, 2)
     case 10: return arr_t(shape, strides, ptr);
     case 11: return py::array(shape, strides, ptr);
     case 12: return py::array(dtype, shape, strides, vptr);
     case 13: return arr_t(shape, ptr);
     case 14: return py::array(shape, ptr);
     case 15: return py::array(dtype, shape, vptr);
     case 16: return arr_t(buf_ndim2);
     case 17: return py::array(buf_ndim2);
     // shape: (3, 2) - post-fill
     case 20: return fill(arr_t(shape, strides));
     case 21: return py::array(shape, strides, ptr); // can't have nullptr due to templated ctor
     case 22: return fill(py::array(dtype, shape, strides));
     case 23: return fill(arr_t(shape));
     case 24: return py::array(shape, ptr); // can't have nullptr due to templated ctor
     case 25: return fill(py::array(dtype, shape));
     case 26: return fill(arr_t(buf_ndim2_null));
     case 27: return fill(py::array(buf_ndim2_null));
     // shape: (6, )
     case 30: return arr_t(6, ptr);
     case 31: return py::array(6, ptr);
     case 32: return py::array(dtype, 6, vptr);
     case 33: return arr_t(buf_ndim1);
     case 34: return py::array(buf_ndim1);
     // shape: (6, )
     case 40: return fill(arr_t(6));
     case 41: return py::array(6, ptr);  // can't have nullptr due to templated ctor
     case 42: return fill(py::array(dtype, 6));
     case 43: return fill(arr_t(buf_ndim1_null));
     case 44: return fill(py::array(buf_ndim1_null));
     }
     return arr_t();
 }

 py::list test_dtype_ctors() {
     py::list list;
     list.append(py::dtype("int32"));
     list.append(py::dtype(std::string("float64")));
     list.append(py::dtype::from_args(py::str("bool")));
     py::list names, offsets, formats;
     py::dict dict;
     names.append(py::str("a")); names.append(py::str("b")); dict["names"] = names;
     offsets.append(py::int_(1)); offsets.append(py::int_(10)); dict["offsets"] = offsets;
     formats.append(py::dtype("int32")); formats.append(py::dtype("float64")); dict["formats"] = formats;
     dict["itemsize"] = py::int_(20);
     list.append(py::dtype::from_args(dict));
     list.append(py::dtype(names, formats, offsets, 20));
     list.append(py::dtype(py::buffer_info((void *) 0, sizeof(unsigned int), "I", 1)));
     list.append(py::dtype(py::buffer_info((void *) 0, 0, "T{i:a:f:b:}", 1)));
     return list;
 }

 TEST_SUBMODULE(numpy_dtypes, m) {
     try { py::module::import("numpy"); }
     catch (...) { return; }

     // typeinfo may be registered before the dtype descriptor for scalar casts to work...
     py::class_<SimpleStruct>(m, "SimpleStruct");

     PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_);
     PYBIND11_NUMPY_DTYPE(PackedStruct, bool_, uint_, float_, ldbl_);
     PYBIND11_NUMPY_DTYPE(NestedStruct, a, b);
     PYBIND11_NUMPY_DTYPE(PartialStruct, bool_, uint_, float_, ldbl_);
     PYBIND11_NUMPY_DTYPE(PartialNestedStruct, a);
     PYBIND11_NUMPY_DTYPE(StringStruct, a, b);
     PYBIND11_NUMPY_DTYPE(ArrayStruct, a, b, c, d);
     PYBIND11_NUMPY_DTYPE(EnumStruct, e1, e2);
     PYBIND11_NUMPY_DTYPE(ComplexStruct, cflt, cdbl);

     // ... or after
     py::class_<PackedStruct>(m, "PackedStruct");

     PYBIND11_NUMPY_DTYPE_EX(StructWithUglyNames, __x__, "x", __y__, "y");

     // If uncommented, this should produce a static_assert failure telling the user that the struct
     // is not a POD type
 //    struct NotPOD { std::string v; NotPOD() : v("hi") {}; };
 //    PYBIND11_NUMPY_DTYPE(NotPOD, v);

     // test_recarray, test_scalar_conversion
     m.def("create_rec_simple", &create_recarray<SimpleStruct>);
     m.def("create_rec_packed", &create_recarray<PackedStruct>);
     m.def("create_rec_nested", [](size_t n) { // test_signature
         py::array_t<NestedStruct, 0> arr = mkarray_via_buffer<NestedStruct>(n);
         auto req = arr.request();
         auto ptr = static_cast<NestedStruct*>(req.ptr);
         for (size_t i = 0; i < n; i++) {
             SET_TEST_VALS(ptr[i].a, i);
             SET_TEST_VALS(ptr[i].b, i + 1);
         }
         return arr;
     });
     m.def("create_rec_partial", &create_recarray<PartialStruct>);
     m.def("create_rec_partial_nested", [](size_t n) {
         py::array_t<PartialNestedStruct, 0> arr = mkarray_via_buffer<PartialNestedStruct>(n);
         auto req = arr.request();
         auto ptr = static_cast<PartialNestedStruct*>(req.ptr);
         for (size_t i = 0; i < n; i++) {
             SET_TEST_VALS(ptr[i].a, i);
         }
         return arr;
     });
     m.def("print_rec_simple", &print_recarray<SimpleStruct>);
     m.def("print_rec_packed", &print_recarray<PackedStruct>);
     m.def("print_rec_nested", &print_recarray<NestedStruct>);

     // test_format_descriptors
     m.def("get_format_unbound", []() { return py::format_descriptor<UnboundStruct>::format(); });
     m.def("print_format_descriptors", []() {
         py::list l;
         for (const auto &fmt : {
             py::format_descriptor<SimpleStruct>::format(),
             py::format_descriptor<PackedStruct>::format(),
             py::format_descriptor<NestedStruct>::format(),
             py::format_descriptor<PartialStruct>::format(),
             py::format_descriptor<PartialNestedStruct>::format(),
             py::format_descriptor<StringStruct>::format(),
             py::format_descriptor<ArrayStruct>::format(),
             py::format_descriptor<EnumStruct>::format(),
             py::format_descriptor<ComplexStruct>::format()
         }) {
             l.append(py::cast(fmt));
         }
         return l;
     });

     // test_dtype
     m.def("print_dtypes", []() {
         py::list l;
         for (const py::handle &d : {
             py::dtype::of<SimpleStruct>(),
             py::dtype::of<PackedStruct>(),
             py::dtype::of<NestedStruct>(),
             py::dtype::of<PartialStruct>(),
             py::dtype::of<PartialNestedStruct>(),
             py::dtype::of<StringStruct>(),
             py::dtype::of<ArrayStruct>(),
             py::dtype::of<EnumStruct>(),
             py::dtype::of<StructWithUglyNames>(),
             py::dtype::of<ComplexStruct>()
         })
             l.append(py::str(d));
         return l;
     });
     m.def("test_dtype_ctors", &test_dtype_ctors);
     m.def("test_dtype_methods", []() {
         py::list list;
         auto dt1 = py::dtype::of<int32_t>();
         auto dt2 = py::dtype::of<SimpleStruct>();
         list.append(dt1); list.append(dt2);
         list.append(py::bool_(dt1.has_fields())); list.append(py::bool_(dt2.has_fields()));
         list.append(py::int_(dt1.itemsize())); list.append(py::int_(dt2.itemsize()));
         return list;
     });
     struct TrailingPaddingStruct {
         int32_t a;
         char b;
     };
     PYBIND11_NUMPY_DTYPE(TrailingPaddingStruct, a, b);
     m.def("trailing_padding_dtype", []() { return py::dtype::of<TrailingPaddingStruct>(); });

     // test_string_array
     m.def("create_string_array", [](bool non_empty) {
         py::array_t<StringStruct, 0> arr = mkarray_via_buffer<StringStruct>(non_empty ? 4 : 0);
         if (non_empty) {
             auto req = arr.request();
             auto ptr = static_cast<StringStruct*>(req.ptr);
             for (ssize_t i = 0; i < req.size * req.itemsize; i++)
                 static_cast<char*>(req.ptr)[i] = 0;
             ptr[1].a[0] = 'a'; ptr[1].b[0] = 'a';
             ptr[2].a[0] = 'a'; ptr[2].b[0] = 'a';
             ptr[3].a[0] = 'a'; ptr[3].b[0] = 'a';

             ptr[2].a[1] = 'b'; ptr[2].b[1] = 'b';
             ptr[3].a[1] = 'b'; ptr[3].b[1] = 'b';

             ptr[3].a[2] = 'c'; ptr[3].b[2] = 'c';
         }
         return arr;
     });
     m.def("print_string_array", &print_recarray<StringStruct>);

     // test_array_array
     m.def("create_array_array", [](size_t n) {
         py::array_t<ArrayStruct, 0> arr = mkarray_via_buffer<ArrayStruct>(n);
         auto ptr = (ArrayStruct *) arr.mutable_data();
         for (size_t i = 0; i < n; i++) {
             for (size_t j = 0; j < 3; j++)
                 for (size_t k = 0; k < 4; k++)
                     ptr[i].a[j][k] = char('A' + (i * 100 + j * 10 + k) % 26);
             for (size_t j = 0; j < 2; j++)
                 ptr[i].b[j] = int32_t(i * 1000 + j);
             for (size_t j = 0; j < 3; j++)
                 ptr[i].c[j] = uint8_t(i * 10 + j);
             for (size_t j = 0; j < 4; j++)
                 for (size_t k = 0; k < 2; k++)
                     ptr[i].d[j][k] = float(i) * 100.0f + float(j) * 10.0f + float(k);
         }
         return arr;
     });
     m.def("print_array_array", &print_recarray<ArrayStruct>);

     // test_enum_array
     m.def("create_enum_array", [](size_t n) {
         py::array_t<EnumStruct, 0> arr = mkarray_via_buffer<EnumStruct>(n);
         auto ptr = (EnumStruct *) arr.mutable_data();
         for (size_t i = 0; i < n; i++) {
             ptr[i].e1 = static_cast<E1>(-1 + ((int) i % 2) * 2);
             ptr[i].e2 = static_cast<E2>(1 + (i % 2));
         }
         return arr;
     });
     m.def("print_enum_array", &print_recarray<EnumStruct>);

     // test_complex_array
     m.def("create_complex_array", [](size_t n) {
         py::array_t<ComplexStruct, 0> arr = mkarray_via_buffer<ComplexStruct>(n);
         auto ptr = (ComplexStruct *) arr.mutable_data();
         for (size_t i = 0; i < n; i++) {
             ptr[i].cflt.real(float(i));
             ptr[i].cflt.imag(float(i) + 0.25f);
             ptr[i].cdbl.real(double(i) + 0.5);
             ptr[i].cdbl.imag(double(i) + 0.75);
         }
         return arr;
     });
     m.def("print_complex_array", &print_recarray<ComplexStruct>);

     // test_array_constructors
     m.def("test_array_ctors", &test_array_ctors);

     // test_compare_buffer_info
     struct CompareStruct {
         bool x;
         uint32_t y;
         float z;
     };
     PYBIND11_NUMPY_DTYPE(CompareStruct, x, y, z);
     m.def("compare_buffer_info", []() {
         py::list list;
         list.append(py::bool_(py::detail::compare_buffer_info<float>::compare(py::buffer_info(nullptr, sizeof(float), "f", 1))));
         list.append(py::bool_(py::detail::compare_buffer_info<unsigned>::compare(py::buffer_info(nullptr, sizeof(int), "I", 1))));
         list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(py::buffer_info(nullptr, sizeof(long), "l", 1))));
         list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(py::buffer_info(nullptr, sizeof(long), sizeof(long) == sizeof(int) ? "i" : "q", 1))));
         list.append(py::bool_(py::detail::compare_buffer_info<CompareStruct>::compare(py::buffer_info(nullptr, sizeof(CompareStruct), "T{?:x:3xI:y:f:z:}", 1))));
         return list;
     });
     m.def("buffer_to_dtype", [](py::buffer& buf) { return py::dtype(buf.request()); });

     // test_scalar_conversion
     m.def("f_simple", [](SimpleStruct s) { return s.uint_ * 10; });
     m.def("f_packed", [](PackedStruct s) { return s.uint_ * 10; });
     m.def("f_nested", [](NestedStruct s) { return s.a.uint_ * 10; });

     // test_register_dtype
     m.def("register_dtype", []() { PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_); });
 }
	/*
	tests/test_numpy_dtypes.cpp -- Structured and compound NumPy dtypes

	Copyright (c) 2016 Ivan Smirnov

	All rights reserved. Use of this source code is governed by a
	BSD-style license that can be found in the LICENSE file.
	*/

	#include "pybind11_tests.h"
	#include <pybind11/numpy.h>

	#ifdef __GNUC__
	#define PYBIND11_PACKED(cls) cls __attribute__((__packed__))
	#else
	#define PYBIND11_PACKED(cls) __pragma(pack(push, 1)) cls __pragma(pack(pop))
	#endif

	namespace py = pybind11;

	struct SimpleStruct {
	bool bool_;
	uint32_t uint_;
	float float_;
	long double ldbl_;
	};

	std::ostream& operator<<(std::ostream& os, const SimpleStruct& v) {
	return os << "s:" << v.bool_ << "," << v.uint_ << "," << v.float_ << "," << v.ldbl_;
	}

	PYBIND11_PACKED(struct PackedStruct {
	bool bool_;
	uint32_t uint_;
	float float_;
	long double ldbl_;
	});

	std::ostream& operator<<(std::ostream& os, const PackedStruct& v) {
	return os << "p:" << v.bool_ << "," << v.uint_ << "," << v.float_ << "," << v.ldbl_;
	}

	PYBIND11_PACKED(struct NestedStruct {
	SimpleStruct a;
	PackedStruct b;
	});

	std::ostream& operator<<(std::ostream& os, const NestedStruct& v) {
	return os << "n:a=" << v.a << ";b=" << v.b;
	}

	struct PartialStruct {
	bool bool_;
	uint32_t uint_;
	float float_;
	uint64_t dummy2;
	long double ldbl_;
	};

	struct PartialNestedStruct {
	uint64_t dummy1;
	PartialStruct a;
	uint64_t dummy2;
	};

	struct UnboundStruct { };

	struct StringStruct {
	char a[3];
	std::array<char, 3> b;
	};

	struct ComplexStruct {
	std::complex<float> cflt;
	std::complex<double> cdbl;
	};

	std::ostream& operator<<(std::ostream& os, const ComplexStruct& v) {
	return os << "c:" << v.cflt << "," << v.cdbl;
	}

	struct ArrayStruct {
	char a[3][4];
	int32_t b[2];
	std::array<uint8_t, 3> c;
	std::array<float, 2> d[4];
	};

	PYBIND11_PACKED(struct StructWithUglyNames {
	int8_t __x__;
	uint64_t __y__;
	});

	enum class E1 : int64_t { A = -1, B = 1 };
	enum E2 : uint8_t { X = 1, Y = 2 };

	PYBIND11_PACKED(struct EnumStruct {
	E1 e1;
	E2 e2;
	});

	std::ostream& operator<<(std::ostream& os, const StringStruct& v) {
	os << "a='";
	for (size_t i = 0; i < 3 && v.a[i]; i++) os << v.a[i];
	os << "',b='";
	for (size_t i = 0; i < 3 && v.b[i]; i++) os << v.b[i];
	return os << "'";
	}

	std::ostream& operator<<(std::ostream& os, const ArrayStruct& v) {
	os << "a={";
	for (int i = 0; i < 3; i++) {
	if (i > 0)
	os << ',';
	os << '{';
	for (int j = 0; j < 3; j++)
	os << v.a[i][j] << ',';
	os << v.a[i][3] << '}';
	}
	os << "},b={" << v.b[0] << ',' << v.b[1];
	os << "},c={" << int(v.c[0]) << ',' << int(v.c[1]) << ',' << int(v.c[2]);
	os << "},d={";
	for (int i = 0; i < 4; i++) {
	if (i > 0)
	os << ',';
	os << '{' << v.d[i][0] << ',' << v.d[i][1] << '}';
	}
	return os << '}';
	}

	std::ostream& operator<<(std::ostream& os, const EnumStruct& v) {
	return os << "e1=" << (v.e1 == E1::A ? "A" : "B") << ",e2=" << (v.e2 == E2::X ? "X" : "Y");
	}

	template <typename T>
	py::array mkarray_via_buffer(size_t n) {
	return py::array(py::buffer_info(nullptr, sizeof(T),
	py::format_descriptor<T>::format(),
	1, { n }, { sizeof(T) }));
	}

	#define SET_TEST_VALS(s, i) do { \
	s.bool_ = (i) % 2 != 0; \
	s.uint_ = (uint32_t) (i); \
	s.float_ = (float) (i) * 1.5f; \
	s.ldbl_ = (long double) (i) * -2.5L; } while (0)

	template <typename S>
	py::array_t<S, 0> create_recarray(size_t n) {
	auto arr = mkarray_via_buffer<S>(n);
	auto req = arr.request();
	auto ptr = static_cast<S*>(req.ptr);
	for (size_t i = 0; i < n; i++) {
	SET_TEST_VALS(ptr[i], i);
	}
	return arr;
	}

	template <typename S>
	py::list print_recarray(py::array_t<S, 0> arr) {
	const auto req = arr.request();
	const auto ptr = static_cast<S*>(req.ptr);
	auto l = py::list();
	for (ssize_t i = 0; i < req.size; i++) {
	std::stringstream ss;
	ss << ptr[i];
	l.append(py::str(ss.str()));
	}
	return l;
	}

	py::array_t<int32_t, 0> test_array_ctors(int i) {
	using arr_t = py::array_t<int32_t, 0>;

	std::vector<int32_t> data { 1, 2, 3, 4, 5, 6 };
	std::vector<ssize_t> shape { 3, 2 };
	std::vector<ssize_t> strides { 8, 4 };

	auto ptr = data.data();
	auto vptr = (void *) ptr;
	auto dtype = py::dtype("int32");

	py::buffer_info buf_ndim1(vptr, 4, "i", 6);
	py::buffer_info buf_ndim1_null(nullptr, 4, "i", 6);
	py::buffer_info buf_ndim2(vptr, 4, "i", 2, shape, strides);
	py::buffer_info buf_ndim2_null(nullptr, 4, "i", 2, shape, strides);

	auto fill = [](py::array arr) {
	auto req = arr.request();
	for (int i = 0; i < 6; i++) ((int32_t *) req.ptr)[i] = i + 1;
	return arr;
	};

	switch (i) {
	// shape: (3, 2)
	case 10: return arr_t(shape, strides, ptr);
	case 11: return py::array(shape, strides, ptr);
	case 12: return py::array(dtype, shape, strides, vptr);
	case 13: return arr_t(shape, ptr);
	case 14: return py::array(shape, ptr);
	case 15: return py::array(dtype, shape, vptr);
	case 16: return arr_t(buf_ndim2);
	case 17: return py::array(buf_ndim2);
	// shape: (3, 2) - post-fill
	case 20: return fill(arr_t(shape, strides));
	case 21: return py::array(shape, strides, ptr); // can't have nullptr due to templated ctor
	case 22: return fill(py::array(dtype, shape, strides));
	case 23: return fill(arr_t(shape));
	case 24: return py::array(shape, ptr); // can't have nullptr due to templated ctor
	case 25: return fill(py::array(dtype, shape));
	case 26: return fill(arr_t(buf_ndim2_null));
	case 27: return fill(py::array(buf_ndim2_null));
	// shape: (6, )
	case 30: return arr_t(6, ptr);
	case 31: return py::array(6, ptr);
	case 32: return py::array(dtype, 6, vptr);
	case 33: return arr_t(buf_ndim1);
	case 34: return py::array(buf_ndim1);
	// shape: (6, )
	case 40: return fill(arr_t(6));
	case 41: return py::array(6, ptr); // can't have nullptr due to templated ctor
	case 42: return fill(py::array(dtype, 6));
	case 43: return fill(arr_t(buf_ndim1_null));
	case 44: return fill(py::array(buf_ndim1_null));
	}
	return arr_t();
	}

	py::list test_dtype_ctors() {
	py::list list;
	list.append(py::dtype("int32"));
	list.append(py::dtype(std::string("float64")));
	list.append(py::dtype::from_args(py::str("bool")));
	py::list names, offsets, formats;
	py::dict dict;
	names.append(py::str("a")); names.append(py::str("b")); dict["names"] = names;
	offsets.append(py::int_(1)); offsets.append(py::int_(10)); dict["offsets"] = offsets;
	formats.append(py::dtype("int32")); formats.append(py::dtype("float64")); dict["formats"] = formats;
	dict["itemsize"] = py::int_(20);
	list.append(py::dtype::from_args(dict));
	list.append(py::dtype(names, formats, offsets, 20));
	list.append(py::dtype(py::buffer_info((void *) 0, sizeof(unsigned int), "I", 1)));
	list.append(py::dtype(py::buffer_info((void *) 0, 0, "T{i:a:f:b:}", 1)));
	return list;
	}

	TEST_SUBMODULE(numpy_dtypes, m) {
	try { py::module::import("numpy"); }
	catch (...) { return; }

	// typeinfo may be registered before the dtype descriptor for scalar casts to work...
	py::class_<SimpleStruct>(m, "SimpleStruct");

	PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_);
	PYBIND11_NUMPY_DTYPE(PackedStruct, bool_, uint_, float_, ldbl_);
	PYBIND11_NUMPY_DTYPE(NestedStruct, a, b);
	PYBIND11_NUMPY_DTYPE(PartialStruct, bool_, uint_, float_, ldbl_);
	PYBIND11_NUMPY_DTYPE(PartialNestedStruct, a);
	PYBIND11_NUMPY_DTYPE(StringStruct, a, b);
	PYBIND11_NUMPY_DTYPE(ArrayStruct, a, b, c, d);
	PYBIND11_NUMPY_DTYPE(EnumStruct, e1, e2);
	PYBIND11_NUMPY_DTYPE(ComplexStruct, cflt, cdbl);

	// ... or after
	py::class_<PackedStruct>(m, "PackedStruct");

	PYBIND11_NUMPY_DTYPE_EX(StructWithUglyNames, __x__, "x", __y__, "y");

	// If uncommented, this should produce a static_assert failure telling the user that the struct
	// is not a POD type
	// struct NotPOD { std::string v; NotPOD() : v("hi") {}; };
	// PYBIND11_NUMPY_DTYPE(NotPOD, v);

	// test_recarray, test_scalar_conversion
	m.def("create_rec_simple", &create_recarray<SimpleStruct>);
	m.def("create_rec_packed", &create_recarray<PackedStruct>);
	m.def("create_rec_nested", [](size_t n) { // test_signature
	py::array_t<NestedStruct, 0> arr = mkarray_via_buffer<NestedStruct>(n);
	auto req = arr.request();
	auto ptr = static_cast<NestedStruct*>(req.ptr);
	for (size_t i = 0; i < n; i++) {
	SET_TEST_VALS(ptr[i].a, i);
	SET_TEST_VALS(ptr[i].b, i + 1);
	}
	return arr;
	});
	m.def("create_rec_partial", &create_recarray<PartialStruct>);
	m.def("create_rec_partial_nested", [](size_t n) {
	py::array_t<PartialNestedStruct, 0> arr = mkarray_via_buffer<PartialNestedStruct>(n);
	auto req = arr.request();
	auto ptr = static_cast<PartialNestedStruct*>(req.ptr);
	for (size_t i = 0; i < n; i++) {
	SET_TEST_VALS(ptr[i].a, i);
	}
	return arr;
	});
	m.def("print_rec_simple", &print_recarray<SimpleStruct>);
	m.def("print_rec_packed", &print_recarray<PackedStruct>);
	m.def("print_rec_nested", &print_recarray<NestedStruct>);

	// test_format_descriptors
	m.def("get_format_unbound", []() { return py::format_descriptor<UnboundStruct>::format(); });
	m.def("print_format_descriptors", []() {
	py::list l;
	for (const auto &fmt : {
	py::format_descriptor<SimpleStruct>::format(),
	py::format_descriptor<PackedStruct>::format(),
	py::format_descriptor<NestedStruct>::format(),
	py::format_descriptor<PartialStruct>::format(),
	py::format_descriptor<PartialNestedStruct>::format(),
	py::format_descriptor<StringStruct>::format(),
	py::format_descriptor<ArrayStruct>::format(),
	py::format_descriptor<EnumStruct>::format(),
	py::format_descriptor<ComplexStruct>::format()
	}) {
	l.append(py::cast(fmt));
	}
	return l;
	});

	// test_dtype
	m.def("print_dtypes", []() {
	py::list l;
	for (const py::handle &d : {
	py::dtype::of<SimpleStruct>(),
	py::dtype::of<PackedStruct>(),
	py::dtype::of<NestedStruct>(),
	py::dtype::of<PartialStruct>(),
	py::dtype::of<PartialNestedStruct>(),
	py::dtype::of<StringStruct>(),
	py::dtype::of<ArrayStruct>(),
	py::dtype::of<EnumStruct>(),
	py::dtype::of<StructWithUglyNames>(),
	py::dtype::of<ComplexStruct>()
	})
	l.append(py::str(d));
	return l;
	});
	m.def("test_dtype_ctors", &test_dtype_ctors);
	m.def("test_dtype_methods", []() {
	py::list list;
	auto dt1 = py::dtype::of<int32_t>();
	auto dt2 = py::dtype::of<SimpleStruct>();
	list.append(dt1); list.append(dt2);
	list.append(py::bool_(dt1.has_fields())); list.append(py::bool_(dt2.has_fields()));
	list.append(py::int_(dt1.itemsize())); list.append(py::int_(dt2.itemsize()));
	return list;
	});
	struct TrailingPaddingStruct {
	int32_t a;
	char b;
	};
	PYBIND11_NUMPY_DTYPE(TrailingPaddingStruct, a, b);
	m.def("trailing_padding_dtype", []() { return py::dtype::of<TrailingPaddingStruct>(); });

	// test_string_array
	m.def("create_string_array", [](bool non_empty) {
	py::array_t<StringStruct, 0> arr = mkarray_via_buffer<StringStruct>(non_empty ? 4 : 0);
	if (non_empty) {
	auto req = arr.request();
	auto ptr = static_cast<StringStruct*>(req.ptr);
	for (ssize_t i = 0; i < req.size * req.itemsize; i++)
	static_cast<char*>(req.ptr)[i] = 0;
	ptr[1].a[0] = 'a'; ptr[1].b[0] = 'a';
	ptr[2].a[0] = 'a'; ptr[2].b[0] = 'a';
	ptr[3].a[0] = 'a'; ptr[3].b[0] = 'a';

	ptr[2].a[1] = 'b'; ptr[2].b[1] = 'b';
	ptr[3].a[1] = 'b'; ptr[3].b[1] = 'b';

	ptr[3].a[2] = 'c'; ptr[3].b[2] = 'c';
	}
	return arr;
	});
	m.def("print_string_array", &print_recarray<StringStruct>);

	// test_array_array
	m.def("create_array_array", [](size_t n) {
	py::array_t<ArrayStruct, 0> arr = mkarray_via_buffer<ArrayStruct>(n);
	auto ptr = (ArrayStruct *) arr.mutable_data();
	for (size_t i = 0; i < n; i++) {
	for (size_t j = 0; j < 3; j++)
	for (size_t k = 0; k < 4; k++)
	ptr[i].a[j][k] = char('A' + (i * 100 + j * 10 + k) % 26);
	for (size_t j = 0; j < 2; j++)
	ptr[i].b[j] = int32_t(i * 1000 + j);
	for (size_t j = 0; j < 3; j++)
	ptr[i].c[j] = uint8_t(i * 10 + j);
	for (size_t j = 0; j < 4; j++)
	for (size_t k = 0; k < 2; k++)
	ptr[i].d[j][k] = float(i) * 100.0f + float(j) * 10.0f + float(k);
	}
	return arr;
	});
	m.def("print_array_array", &print_recarray<ArrayStruct>);

	// test_enum_array
	m.def("create_enum_array", [](size_t n) {
	py::array_t<EnumStruct, 0> arr = mkarray_via_buffer<EnumStruct>(n);
	auto ptr = (EnumStruct *) arr.mutable_data();
	for (size_t i = 0; i < n; i++) {
	ptr[i].e1 = static_cast<E1>(-1 + ((int) i % 2) * 2);
	ptr[i].e2 = static_cast<E2>(1 + (i % 2));
	}
	return arr;
	});
	m.def("print_enum_array", &print_recarray<EnumStruct>);

	// test_complex_array
	m.def("create_complex_array", [](size_t n) {
	py::array_t<ComplexStruct, 0> arr = mkarray_via_buffer<ComplexStruct>(n);
	auto ptr = (ComplexStruct *) arr.mutable_data();
	for (size_t i = 0; i < n; i++) {
	ptr[i].cflt.real(float(i));
	ptr[i].cflt.imag(float(i) + 0.25f);
	ptr[i].cdbl.real(double(i) + 0.5);
	ptr[i].cdbl.imag(double(i) + 0.75);
	}
	return arr;
	});
	m.def("print_complex_array", &print_recarray<ComplexStruct>);

	// test_array_constructors
	m.def("test_array_ctors", &test_array_ctors);

	// test_compare_buffer_info
	struct CompareStruct {
	bool x;
	uint32_t y;
	float z;
	};
	PYBIND11_NUMPY_DTYPE(CompareStruct, x, y, z);
	m.def("compare_buffer_info", []() {
	py::list list;
	list.append(py::bool_(py::detail::compare_buffer_info<float>::compare(py::buffer_info(nullptr, sizeof(float), "f", 1))));
	list.append(py::bool_(py::detail::compare_buffer_info<unsigned>::compare(py::buffer_info(nullptr, sizeof(int), "I", 1))));
	list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(py::buffer_info(nullptr, sizeof(long), "l", 1))));
	list.append(py::bool_(py::detail::compare_buffer_info<long>::compare(py::buffer_info(nullptr, sizeof(long), sizeof(long) == sizeof(int) ? "i" : "q", 1))));
	list.append(py::bool_(py::detail::compare_buffer_info<CompareStruct>::compare(py::buffer_info(nullptr, sizeof(CompareStruct), "T{?:x:3xI:y:f:z:}", 1))));
	return list;
	});
	m.def("buffer_to_dtype", [](py::buffer& buf) { return py::dtype(buf.request()); });

	// test_scalar_conversion
	m.def("f_simple", [](SimpleStruct s) { return s.uint_ * 10; });
	m.def("f_packed", [](PackedStruct s) { return s.uint_ * 10; });
	m.def("f_nested", [](NestedStruct s) { return s.a.uint_ * 10; });

	// test_register_dtype
	m.def("register_dtype", []() { PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_); });
	}