ext/pybind11/tests/test_methods_and_attributes.cpp

   1 /*
   2     tests/test_methods_and_attributes.cpp -- constructors, deconstructors, attribute access,
   3     __str__, argument and return value conventions
   4
   5     Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
   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
  14 class ExampleMandA {
  15 public:
  16     ExampleMandA() { print_default_created(this); }
  17     ExampleMandA(int value) : value(value) { print_created(this, value); }
  18     ExampleMandA(const ExampleMandA &e) : value(e.value) { print_copy_created(this); }
  19     ExampleMandA(ExampleMandA &&e) : value(e.value) { print_move_created(this); }
  20     ~ExampleMandA() { print_destroyed(this); }
  21
  22     std::string toString() {
  23         return "ExampleMandA[value=" + std::to_string(value) + "]";
  24     }
  25
  26     void operator=(const ExampleMandA &e) { print_copy_assigned(this); value = e.value; }
  27     void operator=(ExampleMandA &&e) { print_move_assigned(this); value = e.value; }
  28
  29     void add1(ExampleMandA other) { value += other.value; }         // passing by value
  30     void add2(ExampleMandA &other) { value += other.value; }        // passing by reference
  31     void add3(const ExampleMandA &other) { value += other.value; }  // passing by const reference
  32     void add4(ExampleMandA *other) { value += other->value; }       // passing by pointer
  33     void add5(const ExampleMandA *other) { value += other->value; } // passing by const pointer
  34
  35     void add6(int other) { value += other; }                        // passing by value
  36     void add7(int &other) { value += other; }                       // passing by reference
  37     void add8(const int &other) { value += other; }                 // passing by const reference
  38     void add9(int *other) { value += *other; }                      // passing by pointer
  39     void add10(const int *other) { value += *other; }               // passing by const pointer
  40
  41     ExampleMandA self1() { return *this; }                          // return by value
  42     ExampleMandA &self2() { return *this; }                         // return by reference
  43     const ExampleMandA &self3() { return *this; }                   // return by const reference
  44     ExampleMandA *self4() { return this; }                          // return by pointer
  45     const ExampleMandA *self5() { return this; }                    // return by const pointer
  46
  47     int internal1() { return value; }                               // return by value
  48     int &internal2() { return value; }                              // return by reference
  49     const int &internal3() { return value; }                        // return by const reference
  50     int *internal4() { return &value; }                             // return by pointer
  51     const int *internal5() { return &value; }                       // return by const pointer
  52
  53     py::str overloaded()             { return "()"; }
  54     py::str overloaded(int)          { return "(int)"; }
  55     py::str overloaded(int, float)   { return "(int, float)"; }
  56     py::str overloaded(float, int)   { return "(float, int)"; }
  57     py::str overloaded(int, int)     { return "(int, int)"; }
  58     py::str overloaded(float, float) { return "(float, float)"; }
  59     py::str overloaded(int)          const { return "(int) const"; }
  60     py::str overloaded(int, float)   const { return "(int, float) const"; }
  61     py::str overloaded(float, int)   const { return "(float, int) const"; }
  62     py::str overloaded(int, int)     const { return "(int, int) const"; }
  63     py::str overloaded(float, float) const { return "(float, float) const"; }
  64
  65     static py::str overloaded(float) { return "static float"; }
  66
  67     int value = 0;
  68 };
  69
  70 struct TestProperties {
  71     int value = 1;
  72     static int static_value;
  73
  74     int get() const { return value; }
  75     void set(int v) { value = v; }
  76
  77     static int static_get() { return static_value; }
  78     static void static_set(int v) { static_value = v; }
  79 };
  80 int TestProperties::static_value = 1;
  81
  82 struct TestPropertiesOverride : TestProperties {
  83     int value = 99;
  84     static int static_value;
  85 };
  86 int TestPropertiesOverride::static_value = 99;
  87
  88 struct TestPropRVP {
  89     UserType v1{1};
  90     UserType v2{1};
  91     static UserType sv1;
  92     static UserType sv2;
  93
  94     const UserType &get1() const { return v1; }
  95     const UserType &get2() const { return v2; }
  96     UserType get_rvalue() const { return v2; }
  97     void set1(int v) { v1.set(v); }
  98     void set2(int v) { v2.set(v); }
  99 };
 100 UserType TestPropRVP::sv1(1);
 101 UserType TestPropRVP::sv2(1);
 102
 103 // py::arg/py::arg_v testing: these arguments just record their argument when invoked
 104 class ArgInspector1 { public: std::string arg = "(default arg inspector 1)"; };
 105 class ArgInspector2 { public: std::string arg = "(default arg inspector 2)"; };
 106 class ArgAlwaysConverts { };
 107 namespace pybind11 { namespace detail {
 108 template <> struct type_caster<ArgInspector1> {
 109 public:
 110     PYBIND11_TYPE_CASTER(ArgInspector1, _("ArgInspector1"));
 111
 112     bool load(handle src, bool convert) {
 113         value.arg = "loading ArgInspector1 argument " +
 114             std::string(convert ? "WITH" : "WITHOUT") + " conversion allowed.  "
 115             "Argument value = " + (std::string) str(src);
 116         return true;
 117     }
 118
 119     static handle cast(const ArgInspector1 &src, return_value_policy, handle) {
 120         return str(src.arg).release();
 121     }
 122 };
 123 template <> struct type_caster<ArgInspector2> {
 124 public:
 125     PYBIND11_TYPE_CASTER(ArgInspector2, _("ArgInspector2"));
 126
 127     bool load(handle src, bool convert) {
 128         value.arg = "loading ArgInspector2 argument " +
 129             std::string(convert ? "WITH" : "WITHOUT") + " conversion allowed.  "
 130             "Argument value = " + (std::string) str(src);
 131         return true;
 132     }
 133
 134     static handle cast(const ArgInspector2 &src, return_value_policy, handle) {
 135         return str(src.arg).release();
 136     }
 137 };
 138 template <> struct type_caster<ArgAlwaysConverts> {
 139 public:
 140     PYBIND11_TYPE_CASTER(ArgAlwaysConverts, _("ArgAlwaysConverts"));
 141
 142     bool load(handle, bool convert) {
 143         return convert;
 144     }
 145
 146     static handle cast(const ArgAlwaysConverts &, return_value_policy, handle) {
 147         return py::none().release();
 148     }
 149 };
 150 }}
 151
 152 // test_custom_caster_destruction
 153 class DestructionTester {
 154 public:
 155     DestructionTester() { print_default_created(this); }
 156     ~DestructionTester() { print_destroyed(this); }
 157     DestructionTester(const DestructionTester &) { print_copy_created(this); }
 158     DestructionTester(DestructionTester &&) { print_move_created(this); }
 159     DestructionTester &operator=(const DestructionTester &) { print_copy_assigned(this); return *this; }
 160     DestructionTester &operator=(DestructionTester &&) { print_move_assigned(this); return *this; }
 161 };
 162 namespace pybind11 { namespace detail {
 163 template <> struct type_caster<DestructionTester> {
 164     PYBIND11_TYPE_CASTER(DestructionTester, _("DestructionTester"));
 165     bool load(handle, bool) { return true; }
 166
 167     static handle cast(const DestructionTester &, return_value_policy, handle) {
 168         return py::bool_(true).release();
 169     }
 170 };
 171 }}
 172
 173 // Test None-allowed py::arg argument policy
 174 class NoneTester { public: int answer = 42; };
 175 int none1(const NoneTester &obj) { return obj.answer; }
 176 int none2(NoneTester *obj) { return obj ? obj->answer : -1; }
 177 int none3(std::shared_ptr<NoneTester> &obj) { return obj ? obj->answer : -1; }
 178 int none4(std::shared_ptr<NoneTester> *obj) { return obj && *obj ? (*obj)->answer : -1; }
 179 int none5(std::shared_ptr<NoneTester> obj) { return obj ? obj->answer : -1; }
 180
 181 struct StrIssue {
 182     int val = -1;
 183
 184     StrIssue() = default;
 185     StrIssue(int i) : val{i} {}
 186 };
 187
 188 // Issues #854, #910: incompatible function args when member function/pointer is in unregistered base class
 189 class UnregisteredBase {
 190 public:
 191     void do_nothing() const {}
 192     void increase_value() { rw_value++; ro_value += 0.25; }
 193     void set_int(int v) { rw_value = v; }
 194     int get_int() const { return rw_value; }
 195     double get_double() const { return ro_value; }
 196     int rw_value = 42;
 197     double ro_value = 1.25;
 198 };
 199 class RegisteredDerived : public UnregisteredBase {
 200 public:
 201     using UnregisteredBase::UnregisteredBase;
 202     double sum() const { return rw_value + ro_value; }
 203 };
 204
 205 TEST_SUBMODULE(methods_and_attributes, m) {
 206     // test_methods_and_attributes
 207     py::class_<ExampleMandA> emna(m, "ExampleMandA");
 208     emna.def(py::init<>())
 209         .def(py::init<int>())
 210         .def(py::init<const ExampleMandA&>())
 211         .def("add1", &ExampleMandA::add1)
 212         .def("add2", &ExampleMandA::add2)
 213         .def("add3", &ExampleMandA::add3)
 214         .def("add4", &ExampleMandA::add4)
 215         .def("add5", &ExampleMandA::add5)
 216         .def("add6", &ExampleMandA::add6)
 217         .def("add7", &ExampleMandA::add7)
 218         .def("add8", &ExampleMandA::add8)
 219         .def("add9", &ExampleMandA::add9)
 220         .def("add10", &ExampleMandA::add10)
 221         .def("self1", &ExampleMandA::self1)
 222         .def("self2", &ExampleMandA::self2)
 223         .def("self3", &ExampleMandA::self3)
 224         .def("self4", &ExampleMandA::self4)
 225         .def("self5", &ExampleMandA::self5)
 226         .def("internal1", &ExampleMandA::internal1)
 227         .def("internal2", &ExampleMandA::internal2)
 228         .def("internal3", &ExampleMandA::internal3)
 229         .def("internal4", &ExampleMandA::internal4)
 230         .def("internal5", &ExampleMandA::internal5)
 231 #if defined(PYBIND11_OVERLOAD_CAST)
 232         .def("overloaded", py::overload_cast<>(&ExampleMandA::overloaded))
 233         .def("overloaded", py::overload_cast<int>(&ExampleMandA::overloaded))
 234         .def("overloaded", py::overload_cast<int,   float>(&ExampleMandA::overloaded))
 235         .def("overloaded", py::overload_cast<float,   int>(&ExampleMandA::overloaded))
 236         .def("overloaded", py::overload_cast<int,     int>(&ExampleMandA::overloaded))
 237         .def("overloaded", py::overload_cast<float, float>(&ExampleMandA::overloaded))
 238         .def("overloaded_float", py::overload_cast<float, float>(&ExampleMandA::overloaded))
 239         .def("overloaded_const", py::overload_cast<int         >(&ExampleMandA::overloaded, py::const_))
 240         .def("overloaded_const", py::overload_cast<int,   float>(&ExampleMandA::overloaded, py::const_))
 241         .def("overloaded_const", py::overload_cast<float,   int>(&ExampleMandA::overloaded, py::const_))
 242         .def("overloaded_const", py::overload_cast<int,     int>(&ExampleMandA::overloaded, py::const_))
 243         .def("overloaded_const", py::overload_cast<float, float>(&ExampleMandA::overloaded, py::const_))
 244 #else
 245         .def("overloaded", static_cast<py::str (ExampleMandA::*)()>(&ExampleMandA::overloaded))
 246         .def("overloaded", static_cast<py::str (ExampleMandA::*)(int)>(&ExampleMandA::overloaded))
 247         .def("overloaded", static_cast<py::str (ExampleMandA::*)(int,   float)>(&ExampleMandA::overloaded))
 248         .def("overloaded", static_cast<py::str (ExampleMandA::*)(float,   int)>(&ExampleMandA::overloaded))
 249         .def("overloaded", static_cast<py::str (ExampleMandA::*)(int,     int)>(&ExampleMandA::overloaded))
 250         .def("overloaded", static_cast<py::str (ExampleMandA::*)(float, float)>(&ExampleMandA::overloaded))
 251         .def("overloaded_float", static_cast<py::str (ExampleMandA::*)(float, float)>(&ExampleMandA::overloaded))
 252         .def("overloaded_const", static_cast<py::str (ExampleMandA::*)(int         ) const>(&ExampleMandA::overloaded))
 253         .def("overloaded_const", static_cast<py::str (ExampleMandA::*)(int,   float) const>(&ExampleMandA::overloaded))
 254         .def("overloaded_const", static_cast<py::str (ExampleMandA::*)(float,   int) const>(&ExampleMandA::overloaded))
 255         .def("overloaded_const", static_cast<py::str (ExampleMandA::*)(int,     int) const>(&ExampleMandA::overloaded))
 256         .def("overloaded_const", static_cast<py::str (ExampleMandA::*)(float, float) const>(&ExampleMandA::overloaded))
 257 #endif
 258         // test_no_mixed_overloads
 259         // Raise error if trying to mix static/non-static overloads on the same name:
 260         .def_static("add_mixed_overloads1", []() {
 261             auto emna = py::reinterpret_borrow<py::class_<ExampleMandA>>(py::module::import("pybind11_tests.methods_and_attributes").attr("ExampleMandA"));
 262             emna.def       ("overload_mixed1", static_cast<py::str (ExampleMandA::*)(int, int)>(&ExampleMandA::overloaded))
 263                 .def_static("overload_mixed1", static_cast<py::str (              *)(float   )>(&ExampleMandA::overloaded));
 264         })
 265         .def_static("add_mixed_overloads2", []() {
 266             auto emna = py::reinterpret_borrow<py::class_<ExampleMandA>>(py::module::import("pybind11_tests.methods_and_attributes").attr("ExampleMandA"));
 267             emna.def_static("overload_mixed2", static_cast<py::str (              *)(float   )>(&ExampleMandA::overloaded))
 268                 .def       ("overload_mixed2", static_cast<py::str (ExampleMandA::*)(int, int)>(&ExampleMandA::overloaded));
 269         })
 270         .def("__str__", &ExampleMandA::toString)
 271         .def_readwrite("value", &ExampleMandA::value);
 272
 273     // test_copy_method
 274     // Issue #443: can't call copied methods in Python 3
 275     emna.attr("add2b") = emna.attr("add2");
 276
 277     // test_properties, test_static_properties, test_static_cls
 278     py::class_<TestProperties>(m, "TestProperties")
 279         .def(py::init<>())
 280         .def_readonly("def_readonly", &TestProperties::value)
 281         .def_readwrite("def_readwrite", &TestProperties::value)
 282         .def_property_readonly("def_property_readonly", &TestProperties::get)
 283         .def_property("def_property", &TestProperties::get, &TestProperties::set)
 284         .def_readonly_static("def_readonly_static", &TestProperties::static_value)
 285         .def_readwrite_static("def_readwrite_static", &TestProperties::static_value)
 286         .def_property_readonly_static("def_property_readonly_static",
 287                                       [](py::object) { return TestProperties::static_get(); })
 288         .def_property_static("def_property_static",
 289                              [](py::object) { return TestProperties::static_get(); },
 290                              [](py::object, int v) { TestProperties::static_set(v); })
 291         .def_property_static("static_cls",
 292                              [](py::object cls) { return cls; },
 293                              [](py::object cls, py::function f) { f(cls); });
 294
 295     py::class_<TestPropertiesOverride, TestProperties>(m, "TestPropertiesOverride")
 296         .def(py::init<>())
 297         .def_readonly("def_readonly", &TestPropertiesOverride::value)
 298         .def_readonly_static("def_readonly_static", &TestPropertiesOverride::static_value);
 299
 300     auto static_get1 = [](py::object) -> const UserType & { return TestPropRVP::sv1; };
 301     auto static_get2 = [](py::object) -> const UserType & { return TestPropRVP::sv2; };
 302     auto static_set1 = [](py::object, int v) { TestPropRVP::sv1.set(v); };
 303     auto static_set2 = [](py::object, int v) { TestPropRVP::sv2.set(v); };
 304     auto rvp_copy = py::return_value_policy::copy;
 305
 306     // test_property_return_value_policies
 307     py::class_<TestPropRVP>(m, "TestPropRVP")
 308         .def(py::init<>())
 309         .def_property_readonly("ro_ref", &TestPropRVP::get1)
 310         .def_property_readonly("ro_copy", &TestPropRVP::get2, rvp_copy)
 311         .def_property_readonly("ro_func", py::cpp_function(&TestPropRVP::get2, rvp_copy))
 312         .def_property("rw_ref", &TestPropRVP::get1, &TestPropRVP::set1)
 313         .def_property("rw_copy", &TestPropRVP::get2, &TestPropRVP::set2, rvp_copy)
 314         .def_property("rw_func", py::cpp_function(&TestPropRVP::get2, rvp_copy), &TestPropRVP::set2)
 315         .def_property_readonly_static("static_ro_ref", static_get1)
 316         .def_property_readonly_static("static_ro_copy", static_get2, rvp_copy)
 317         .def_property_readonly_static("static_ro_func", py::cpp_function(static_get2, rvp_copy))
 318         .def_property_static("static_rw_ref", static_get1, static_set1)
 319         .def_property_static("static_rw_copy", static_get2, static_set2, rvp_copy)
 320         .def_property_static("static_rw_func", py::cpp_function(static_get2, rvp_copy), static_set2)
 321         // test_property_rvalue_policy
 322         .def_property_readonly("rvalue", &TestPropRVP::get_rvalue)
 323         .def_property_readonly_static("static_rvalue", [](py::object) { return UserType(1); });
 324
 325     // test_metaclass_override
 326     struct MetaclassOverride { };
 327     py::class_<MetaclassOverride>(m, "MetaclassOverride", py::metaclass((PyObject *) &PyType_Type))
 328         .def_property_readonly_static("readonly", [](py::object) { return 1; });
 329
 330 #if !defined(PYPY_VERSION)
 331     // test_dynamic_attributes
 332     class DynamicClass {
 333     public:
 334         DynamicClass() { print_default_created(this); }
 335         ~DynamicClass() { print_destroyed(this); }
 336     };
 337     py::class_<DynamicClass>(m, "DynamicClass", py::dynamic_attr())
 338         .def(py::init());
 339
 340     class CppDerivedDynamicClass : public DynamicClass { };
 341     py::class_<CppDerivedDynamicClass, DynamicClass>(m, "CppDerivedDynamicClass")
 342         .def(py::init());
 343 #endif
 344
 345     // test_noconvert_args
 346     //
 347     // Test converting.  The ArgAlwaysConverts is just there to make the first no-conversion pass
 348     // fail so that our call always ends up happening via the second dispatch (the one that allows
 349     // some conversion).
 350     class ArgInspector {
 351     public:
 352         ArgInspector1 f(ArgInspector1 a, ArgAlwaysConverts) { return a; }
 353         std::string g(ArgInspector1 a, const ArgInspector1 &b, int c, ArgInspector2 *d, ArgAlwaysConverts) {
 354             return a.arg + "\n" + b.arg + "\n" + std::to_string(c) + "\n" + d->arg;
 355         }
 356         static ArgInspector2 h(ArgInspector2 a, ArgAlwaysConverts) { return a; }
 357     };
 358     py::class_<ArgInspector>(m, "ArgInspector")
 359         .def(py::init<>())
 360         .def("f", &ArgInspector::f, py::arg(), py::arg() = ArgAlwaysConverts())
 361         .def("g", &ArgInspector::g, "a"_a.noconvert(), "b"_a, "c"_a.noconvert()=13, "d"_a=ArgInspector2(), py::arg() = ArgAlwaysConverts())
 362         .def_static("h", &ArgInspector::h, py::arg().noconvert(), py::arg() = ArgAlwaysConverts())
 363         ;
 364     m.def("arg_inspect_func", [](ArgInspector2 a, ArgInspector1 b, ArgAlwaysConverts) { return a.arg + "\n" + b.arg; },
 365             py::arg().noconvert(false), py::arg_v(nullptr, ArgInspector1()).noconvert(true), py::arg() = ArgAlwaysConverts());
 366
 367     m.def("floats_preferred", [](double f) { return 0.5 * f; }, py::arg("f"));
 368     m.def("floats_only", [](double f) { return 0.5 * f; }, py::arg("f").noconvert());
 369     m.def("ints_preferred", [](int i) { return i / 2; }, py::arg("i"));
 370     m.def("ints_only", [](int i) { return i / 2; }, py::arg("i").noconvert());
 371
 372     // test_bad_arg_default
 373     // Issue/PR #648: bad arg default debugging output
 374 #if !defined(NDEBUG)
 375     m.attr("debug_enabled") = true;
 376 #else
 377     m.attr("debug_enabled") = false;
 378 #endif
 379     m.def("bad_arg_def_named", []{
 380         auto m = py::module::import("pybind11_tests");
 381         m.def("should_fail", [](int, UnregisteredType) {}, py::arg(), py::arg("a") = UnregisteredType());
 382     });
 383     m.def("bad_arg_def_unnamed", []{
 384         auto m = py::module::import("pybind11_tests");
 385         m.def("should_fail", [](int, UnregisteredType) {}, py::arg(), py::arg() = UnregisteredType());
 386     });
 387
 388     // test_accepts_none
 389     py::class_<NoneTester, std::shared_ptr<NoneTester>>(m, "NoneTester")
 390         .def(py::init<>());
 391     m.def("no_none1", &none1, py::arg().none(false));
 392     m.def("no_none2", &none2, py::arg().none(false));
 393     m.def("no_none3", &none3, py::arg().none(false));
 394     m.def("no_none4", &none4, py::arg().none(false));
 395     m.def("no_none5", &none5, py::arg().none(false));
 396     m.def("ok_none1", &none1);
 397     m.def("ok_none2", &none2, py::arg().none(true));
 398     m.def("ok_none3", &none3);
 399     m.def("ok_none4", &none4, py::arg().none(true));
 400     m.def("ok_none5", &none5);
 401
 402     // test_str_issue
 403     // Issue #283: __str__ called on uninitialized instance when constructor arguments invalid
 404     py::class_<StrIssue>(m, "StrIssue")
 405         .def(py::init<int>())
 406         .def(py::init<>())
 407         .def("__str__", [](const StrIssue &si) {
 408             return "StrIssue[" + std::to_string(si.val) + "]"; }
 409         );
 410
 411     // test_unregistered_base_implementations
 412     //
 413     // Issues #854/910: incompatible function args when member function/pointer is in unregistered
 414     // base class The methods and member pointers below actually resolve to members/pointers in
 415     // UnregisteredBase; before this test/fix they would be registered via lambda with a first
 416     // argument of an unregistered type, and thus uncallable.
 417     py::class_<RegisteredDerived>(m, "RegisteredDerived")
 418         .def(py::init<>())
 419         .def("do_nothing", &RegisteredDerived::do_nothing)
 420         .def("increase_value", &RegisteredDerived::increase_value)
 421         .def_readwrite("rw_value", &RegisteredDerived::rw_value)
 422         .def_readonly("ro_value", &RegisteredDerived::ro_value)
 423         // These should trigger a static_assert if uncommented
 424         //.def_readwrite("fails", &UserType::value) // should trigger a static_assert if uncommented
 425         //.def_readonly("fails", &UserType::value) // should trigger a static_assert if uncommented
 426         .def_property("rw_value_prop", &RegisteredDerived::get_int, &RegisteredDerived::set_int)
 427         .def_property_readonly("ro_value_prop", &RegisteredDerived::get_double)
 428         // This one is in the registered class:
 429         .def("sum", &RegisteredDerived::sum)
 430         ;
 431
 432     using Adapted = decltype(py::method_adaptor<RegisteredDerived>(&RegisteredDerived::do_nothing));
 433     static_assert(std::is_same<Adapted, void (RegisteredDerived::*)() const>::value, "");
 434
 435     // test_custom_caster_destruction
 436     // Test that `take_ownership` works on types with a custom type caster when given a pointer
 437
 438     // default policy: don't take ownership:
 439     m.def("custom_caster_no_destroy", []() { static auto *dt = new DestructionTester(); return dt; });
 440
 441     m.def("custom_caster_destroy", []() { return new DestructionTester(); },
 442             py::return_value_policy::take_ownership); // Takes ownership: destroy when finished
 443     m.def("custom_caster_destroy_const", []() -> const DestructionTester * { return new DestructionTester(); },
 444             py::return_value_policy::take_ownership); // Likewise (const doesn't inhibit destruction)
 445     m.def("destruction_tester_cstats", &ConstructorStats::get<DestructionTester>, py::return_value_policy::reference);
 446 }