test_factory_constructors.cpp revision 12391:ceeca8b41e4b 
1/*
2    tests/test_factory_constructors.cpp -- tests construction from a factory function
3                                           via py::init_factory()
4
5    Copyright (c) 2017 Jason Rhinelander <jason@imaginary.ca>
6
7    All rights reserved. Use of this source code is governed by a
8    BSD-style license that can be found in the LICENSE file.
9*/
10
11#include "pybind11_tests.h"
12#include "constructor_stats.h"
13#include <cmath>
14
15// Classes for testing python construction via C++ factory function:
16// Not publically constructible, copyable, or movable:
17class TestFactory1 {
18    friend class TestFactoryHelper;
19    TestFactory1() : value("(empty)") { print_default_created(this); }
20    TestFactory1(int v) : value(std::to_string(v)) { print_created(this, value); }
21    TestFactory1(std::string v) : value(std::move(v)) { print_created(this, value); }
22    TestFactory1(TestFactory1 &&) = delete;
23    TestFactory1(const TestFactory1 &) = delete;
24    TestFactory1 &operator=(TestFactory1 &&) = delete;
25    TestFactory1 &operator=(const TestFactory1 &) = delete;
26public:
27    std::string value;
28    ~TestFactory1() { print_destroyed(this); }
29};
30// Non-public construction, but moveable:
31class TestFactory2 {
32    friend class TestFactoryHelper;
33    TestFactory2() : value("(empty2)") { print_default_created(this); }
34    TestFactory2(int v) : value(std::to_string(v)) { print_created(this, value); }
35    TestFactory2(std::string v) : value(std::move(v)) { print_created(this, value); }
36public:
37    TestFactory2(TestFactory2 &&m) { value = std::move(m.value); print_move_created(this); }
38    TestFactory2 &operator=(TestFactory2 &&m) { value = std::move(m.value); print_move_assigned(this); return *this; }
39    std::string value;
40    ~TestFactory2() { print_destroyed(this); }
41};
42// Mixed direct/factory construction:
43class TestFactory3 {
44protected:
45    friend class TestFactoryHelper;
46    TestFactory3() : value("(empty3)") { print_default_created(this); }
47    TestFactory3(int v) : value(std::to_string(v)) { print_created(this, value); }
48public:
49    TestFactory3(std::string v) : value(std::move(v)) { print_created(this, value); }
50    TestFactory3(TestFactory3 &&m) { value = std::move(m.value); print_move_created(this); }
51    TestFactory3 &operator=(TestFactory3 &&m) { value = std::move(m.value); print_move_assigned(this); return *this; }
52    std::string value;
53    virtual ~TestFactory3() { print_destroyed(this); }
54};
55// Inheritance test
56class TestFactory4 : public TestFactory3 {
57public:
58    TestFactory4() : TestFactory3() { print_default_created(this); }
59    TestFactory4(int v) : TestFactory3(v) { print_created(this, v); }
60    virtual ~TestFactory4() { print_destroyed(this); }
61};
62// Another class for an invalid downcast test
63class TestFactory5 : public TestFactory3 {
64public:
65    TestFactory5(int i) : TestFactory3(i) { print_created(this, i); }
66    virtual ~TestFactory5() { print_destroyed(this); }
67};
68
69class TestFactory6 {
70protected:
71    int value;
72    bool alias = false;
73public:
74    TestFactory6(int i) : value{i} { print_created(this, i); }
75    TestFactory6(TestFactory6 &&f) { print_move_created(this); value = f.value; alias = f.alias; }
76    TestFactory6(const TestFactory6 &f) { print_copy_created(this); value = f.value; alias = f.alias; }
77    virtual ~TestFactory6() { print_destroyed(this); }
78    virtual int get() { return value; }
79    bool has_alias() { return alias; }
80};
81class PyTF6 : public TestFactory6 {
82public:
83    // Special constructor that allows the factory to construct a PyTF6 from a TestFactory6 only
84    // when an alias is needed:
85    PyTF6(TestFactory6 &&base) : TestFactory6(std::move(base)) { alias = true; print_created(this, "move", value); }
86    PyTF6(int i) : TestFactory6(i) { alias = true; print_created(this, i); }
87    PyTF6(PyTF6 &&f) : TestFactory6(std::move(f)) { print_move_created(this); }
88    PyTF6(const PyTF6 &f) : TestFactory6(f) { print_copy_created(this); }
89    PyTF6(std::string s) : TestFactory6((int) s.size()) { alias = true; print_created(this, s); }
90    virtual ~PyTF6() { print_destroyed(this); }
91    int get() override { PYBIND11_OVERLOAD(int, TestFactory6, get, /*no args*/); }
92};
93
94class TestFactory7 {
95protected:
96    int value;
97    bool alias = false;
98public:
99    TestFactory7(int i) : value{i} { print_created(this, i); }
100    TestFactory7(TestFactory7 &&f) { print_move_created(this); value = f.value; alias = f.alias; }
101    TestFactory7(const TestFactory7 &f) { print_copy_created(this); value = f.value; alias = f.alias; }
102    virtual ~TestFactory7() { print_destroyed(this); }
103    virtual int get() { return value; }
104    bool has_alias() { return alias; }
105};
106class PyTF7 : public TestFactory7 {
107public:
108    PyTF7(int i) : TestFactory7(i) { alias = true; print_created(this, i); }
109    PyTF7(PyTF7 &&f) : TestFactory7(std::move(f)) { print_move_created(this); }
110    PyTF7(const PyTF7 &f) : TestFactory7(f) { print_copy_created(this); }
111    virtual ~PyTF7() { print_destroyed(this); }
112    int get() override { PYBIND11_OVERLOAD(int, TestFactory7, get, /*no args*/); }
113};
114
115
116class TestFactoryHelper {
117public:
118    // Non-movable, non-copyable type:
119    // Return via pointer:
120    static TestFactory1 *construct1() { return new TestFactory1(); }
121    // Holder:
122    static std::unique_ptr<TestFactory1> construct1(int a) { return std::unique_ptr<TestFactory1>(new TestFactory1(a)); }
123    // pointer again
124    static TestFactory1 *construct1_string(std::string a) { return new TestFactory1(a); }
125
126    // Moveable type:
127    // pointer:
128    static TestFactory2 *construct2() { return new TestFactory2(); }
129    // holder:
130    static std::unique_ptr<TestFactory2> construct2(int a) { return std::unique_ptr<TestFactory2>(new TestFactory2(a)); }
131    // by value moving:
132    static TestFactory2 construct2(std::string a) { return TestFactory2(a); }
133
134    // shared_ptr holder type:
135    // pointer:
136    static TestFactory3 *construct3() { return new TestFactory3(); }
137    // holder:
138    static std::shared_ptr<TestFactory3> construct3(int a) { return std::shared_ptr<TestFactory3>(new TestFactory3(a)); }
139};
140
141TEST_SUBMODULE(factory_constructors, m) {
142
143    // Define various trivial types to allow simpler overload resolution:
144    py::module m_tag = m.def_submodule("tag");
145#define MAKE_TAG_TYPE(Name) \
146    struct Name##_tag {}; \
147    py::class_<Name##_tag>(m_tag, #Name "_tag").def(py::init<>()); \
148    m_tag.attr(#Name) = py::cast(Name##_tag{})
149    MAKE_TAG_TYPE(pointer);
150    MAKE_TAG_TYPE(unique_ptr);
151    MAKE_TAG_TYPE(move);
152    MAKE_TAG_TYPE(shared_ptr);
153    MAKE_TAG_TYPE(derived);
154    MAKE_TAG_TYPE(TF4);
155    MAKE_TAG_TYPE(TF5);
156    MAKE_TAG_TYPE(null_ptr);
157    MAKE_TAG_TYPE(base);
158    MAKE_TAG_TYPE(invalid_base);
159    MAKE_TAG_TYPE(alias);
160    MAKE_TAG_TYPE(unaliasable);
161    MAKE_TAG_TYPE(mixed);
162
163    // test_init_factory_basic, test_bad_type
164    py::class_<TestFactory1>(m, "TestFactory1")
165        .def(py::init([](unique_ptr_tag, int v) { return TestFactoryHelper::construct1(v); }))
166        .def(py::init(&TestFactoryHelper::construct1_string)) // raw function pointer
167        .def(py::init([](pointer_tag) { return TestFactoryHelper::construct1(); }))
168        .def(py::init([](py::handle, int v, py::handle) { return TestFactoryHelper::construct1(v); }))
169        .def_readwrite("value", &TestFactory1::value)
170        ;
171    py::class_<TestFactory2>(m, "TestFactory2")
172        .def(py::init([](pointer_tag, int v) { return TestFactoryHelper::construct2(v); }))
173        .def(py::init([](unique_ptr_tag, std::string v) { return TestFactoryHelper::construct2(v); }))
174        .def(py::init([](move_tag) { return TestFactoryHelper::construct2(); }))
175        .def_readwrite("value", &TestFactory2::value)
176        ;
177
178    // Stateful & reused:
179    int c = 1;
180    auto c4a = [c](pointer_tag, TF4_tag, int a) { (void) c; return new TestFactory4(a);};
181
182    // test_init_factory_basic, test_init_factory_casting
183    py::class_<TestFactory3, std::shared_ptr<TestFactory3>>(m, "TestFactory3")
184        .def(py::init([](pointer_tag, int v) { return TestFactoryHelper::construct3(v); }))
185        .def(py::init([](shared_ptr_tag) { return TestFactoryHelper::construct3(); }))
186        .def("__init__", [](TestFactory3 &self, std::string v) { new (&self) TestFactory3(v); }) // placement-new ctor
187
188        // factories returning a derived type:
189        .def(py::init(c4a)) // derived ptr
190        .def(py::init([](pointer_tag, TF5_tag, int a) { return new TestFactory5(a); }))
191        // derived shared ptr:
192        .def(py::init([](shared_ptr_tag, TF4_tag, int a) { return std::make_shared<TestFactory4>(a); }))
193        .def(py::init([](shared_ptr_tag, TF5_tag, int a) { return std::make_shared<TestFactory5>(a); }))
194
195        // Returns nullptr:
196        .def(py::init([](null_ptr_tag) { return (TestFactory3 *) nullptr; }))
197
198        .def_readwrite("value", &TestFactory3::value)
199        ;
200
201    // test_init_factory_casting
202    py::class_<TestFactory4, TestFactory3, std::shared_ptr<TestFactory4>>(m, "TestFactory4")
203        .def(py::init(c4a)) // pointer
204        ;
205
206    // Doesn't need to be registered, but registering makes getting ConstructorStats easier:
207    py::class_<TestFactory5, TestFactory3, std::shared_ptr<TestFactory5>>(m, "TestFactory5");
208
209    // test_init_factory_alias
210    // Alias testing
211    py::class_<TestFactory6, PyTF6>(m, "TestFactory6")
212        .def(py::init([](base_tag, int i) { return TestFactory6(i); }))
213        .def(py::init([](alias_tag, int i) { return PyTF6(i); }))
214        .def(py::init([](alias_tag, std::string s) { return PyTF6(s); }))
215        .def(py::init([](alias_tag, pointer_tag, int i) { return new PyTF6(i); }))
216        .def(py::init([](base_tag, pointer_tag, int i) { return new TestFactory6(i); }))
217        .def(py::init([](base_tag, alias_tag, pointer_tag, int i) { return (TestFactory6 *) new PyTF6(i); }))
218
219        .def("get", &TestFactory6::get)
220        .def("has_alias", &TestFactory6::has_alias)
221
222        .def_static("get_cstats", &ConstructorStats::get<TestFactory6>, py::return_value_policy::reference)
223        .def_static("get_alias_cstats", &ConstructorStats::get<PyTF6>, py::return_value_policy::reference)
224        ;
225
226    // test_init_factory_dual
227    // Separate alias constructor testing
228    py::class_<TestFactory7, PyTF7, std::shared_ptr<TestFactory7>>(m, "TestFactory7")
229        .def(py::init(
230            [](int i) { return TestFactory7(i); },
231            [](int i) { return PyTF7(i); }))
232        .def(py::init(
233            [](pointer_tag, int i) { return new TestFactory7(i); },
234            [](pointer_tag, int i) { return new PyTF7(i); }))
235        .def(py::init(
236            [](mixed_tag, int i) { return new TestFactory7(i); },
237            [](mixed_tag, int i) { return PyTF7(i); }))
238        .def(py::init(
239            [](mixed_tag, std::string s) { return TestFactory7((int) s.size()); },
240            [](mixed_tag, std::string s) { return new PyTF7((int) s.size()); }))
241        .def(py::init(
242            [](base_tag, pointer_tag, int i) { return new TestFactory7(i); },
243            [](base_tag, pointer_tag, int i) { return (TestFactory7 *) new PyTF7(i); }))
244        .def(py::init(
245            [](alias_tag, pointer_tag, int i) { return new PyTF7(i); },
246            [](alias_tag, pointer_tag, int i) { return new PyTF7(10*i); }))
247        .def(py::init(
248            [](shared_ptr_tag, base_tag, int i) { return std::make_shared<TestFactory7>(i); },
249            [](shared_ptr_tag, base_tag, int i) { auto *p = new PyTF7(i); return std::shared_ptr<TestFactory7>(p); }))
250        .def(py::init(
251            [](shared_ptr_tag, invalid_base_tag, int i) { return std::make_shared<TestFactory7>(i); },
252            [](shared_ptr_tag, invalid_base_tag, int i) { return std::make_shared<TestFactory7>(i); })) // <-- invalid alias factory
253
254        .def("get", &TestFactory7::get)
255        .def("has_alias", &TestFactory7::has_alias)
256
257        .def_static("get_cstats", &ConstructorStats::get<TestFactory7>, py::return_value_policy::reference)
258        .def_static("get_alias_cstats", &ConstructorStats::get<PyTF7>, py::return_value_policy::reference)
259        ;
260
261    // test_placement_new_alternative
262    // Class with a custom new operator but *without* a placement new operator (issue #948)
263    class NoPlacementNew {
264    public:
265        NoPlacementNew(int i) : i(i) { }
266        static void *operator new(std::size_t s) {
267            auto *p = ::operator new(s);
268            py::print("operator new called, returning", reinterpret_cast<uintptr_t>(p));
269            return p;
270        }
271        static void operator delete(void *p) {
272            py::print("operator delete called on", reinterpret_cast<uintptr_t>(p));
273            ::operator delete(p);
274        }
275        int i;
276    };
277    // As of 2.2, `py::init<args>` no longer requires placement new
278    py::class_<NoPlacementNew>(m, "NoPlacementNew")
279        .def(py::init<int>())
280        .def(py::init([]() { return new NoPlacementNew(100); }))
281        .def_readwrite("i", &NoPlacementNew::i)
282        ;
283
284
285    // test_reallocations
286    // Class that has verbose operator_new/operator_delete calls
287    struct NoisyAlloc {
288        NoisyAlloc(int i) { py::print(py::str("NoisyAlloc(int {})").format(i)); }
289        NoisyAlloc(double d) { py::print(py::str("NoisyAlloc(double {})").format(d)); }
290        ~NoisyAlloc() { py::print("~NoisyAlloc()"); }
291
292        static void *operator new(size_t s) { py::print("noisy new"); return ::operator new(s); }
293        static void *operator new(size_t, void *p) { py::print("noisy placement new"); return p; }
294        static void operator delete(void *p, size_t) { py::print("noisy delete"); ::operator delete(p); }
295        static void operator delete(void *, void *) { py::print("noisy placement delete"); }
296#if defined(_MSC_VER) && _MSC_VER < 1910
297        // MSVC 2015 bug: the above "noisy delete" isn't invoked (fixed in MSVC 2017)
298        static void operator delete(void *p) { py::print("noisy delete"); ::operator delete(p); }
299#endif
300    };
301    py::class_<NoisyAlloc>(m, "NoisyAlloc")
302        // Since these overloads have the same number of arguments, the dispatcher will try each of
303        // them until the arguments convert.  Thus we can get a pre-allocation here when passing a
304        // single non-integer:
305        .def("__init__", [](NoisyAlloc *a, int i) { new (a) NoisyAlloc(i); }) // Regular constructor, runs first, requires preallocation
306        .def(py::init([](double d) { return new NoisyAlloc(d); }))
307
308        // The two-argument version: first the factory pointer overload.
309        .def(py::init([](int i, int) { return new NoisyAlloc(i); }))
310        // Return-by-value:
311        .def(py::init([](double d, int) { return NoisyAlloc(d); }))
312        // Old-style placement new init; requires preallocation
313        .def("__init__", [](NoisyAlloc &a, double d, double) { new (&a) NoisyAlloc(d); })
314        // Requires deallocation of previous overload preallocated value:
315        .def(py::init([](int i, double) { return new NoisyAlloc(i); }))
316        // Regular again: requires yet another preallocation
317        .def("__init__", [](NoisyAlloc &a, int i, std::string) { new (&a) NoisyAlloc(i); })
318        ;
319
320
321
322
323    // static_assert testing (the following def's should all fail with appropriate compilation errors):
324#if 0
325    struct BadF1Base {};
326    struct BadF1 : BadF1Base {};
327    struct PyBadF1 : BadF1 {};
328    py::class_<BadF1, PyBadF1, std::shared_ptr<BadF1>> bf1(m, "BadF1");
329    // wrapped factory function must return a compatible pointer, holder, or value
330    bf1.def(py::init([]() { return 3; }));
331    // incompatible factory function pointer return type
332    bf1.def(py::init([]() { static int three = 3; return &three; }));
333    // incompatible factory function std::shared_ptr<T> return type: cannot convert shared_ptr<T> to holder
334    // (non-polymorphic base)
335    bf1.def(py::init([]() { return std::shared_ptr<BadF1Base>(new BadF1()); }));
336#endif
337}
338