ext/pybind11/tests/test_class.cpp - public/gem5 - Git at Google

 /*
     tests/test_class.cpp -- test py::class_ definitions and basic functionality

     Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>

     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 "constructor_stats.h"
 #include "local_bindings.h"
 #include <pybind11/stl.h>

 #if defined(_MSC_VER)
 #  pragma warning(disable: 4324) // warning C4324: structure was padded due to alignment specifier
 #endif

 // test_brace_initialization
 struct NoBraceInitialization {
     NoBraceInitialization(std::vector<int> v) : vec{std::move(v)} {}
     template <typename T>
     NoBraceInitialization(std::initializer_list<T> l) : vec(l) {}

     std::vector<int> vec;
 };

 TEST_SUBMODULE(class_, m) {
     // test_instance
     struct NoConstructor {
         NoConstructor() = default;
         NoConstructor(const NoConstructor &) = default;
         NoConstructor(NoConstructor &&) = default;
         static NoConstructor *new_instance() {
             auto *ptr = new NoConstructor();
             print_created(ptr, "via new_instance");
             return ptr;
         }
         ~NoConstructor() { print_destroyed(this); }
     };

     py::class_<NoConstructor>(m, "NoConstructor")
         .def_static("new_instance", &NoConstructor::new_instance, "Return an instance");

     // test_inheritance
     class Pet {
     public:
         Pet(const std::string &name, const std::string &species)
             : m_name(name), m_species(species) {}
         std::string name() const { return m_name; }
         std::string species() const { return m_species; }
     private:
         std::string m_name;
         std::string m_species;
     };

     class Dog : public Pet {
     public:
         Dog(const std::string &name) : Pet(name, "dog") {}
         std::string bark() const { return "Woof!"; }
     };

     class Rabbit : public Pet {
     public:
         Rabbit(const std::string &name) : Pet(name, "parrot") {}
     };

     class Hamster : public Pet {
     public:
         Hamster(const std::string &name) : Pet(name, "rodent") {}
     };

     class Chimera : public Pet {
         Chimera() : Pet("Kimmy", "chimera") {}
     };

     py::class_<Pet> pet_class(m, "Pet");
     pet_class
         .def(py::init<std::string, std::string>())
         .def("name", &Pet::name)
         .def("species", &Pet::species);

     /* One way of declaring a subclass relationship: reference parent's class_ object */
     py::class_<Dog>(m, "Dog", pet_class)
         .def(py::init<std::string>());

     /* Another way of declaring a subclass relationship: reference parent's C++ type */
     py::class_<Rabbit, Pet>(m, "Rabbit")
         .def(py::init<std::string>());

     /* And another: list parent in class template arguments */
     py::class_<Hamster, Pet>(m, "Hamster")
         .def(py::init<std::string>());

     /* Constructors are not inherited by default */
     py::class_<Chimera, Pet>(m, "Chimera");

     m.def("pet_name_species", [](const Pet &pet) { return pet.name() + " is a " + pet.species(); });
     m.def("dog_bark", [](const Dog &dog) { return dog.bark(); });

     // test_automatic_upcasting
     struct BaseClass {
         BaseClass() = default;
         BaseClass(const BaseClass &) = default;
         BaseClass(BaseClass &&) = default;
         virtual ~BaseClass() {}
     };
     struct DerivedClass1 : BaseClass { };
     struct DerivedClass2 : BaseClass { };

     py::class_<BaseClass>(m, "BaseClass").def(py::init<>());
     py::class_<DerivedClass1>(m, "DerivedClass1").def(py::init<>());
     py::class_<DerivedClass2>(m, "DerivedClass2").def(py::init<>());

     m.def("return_class_1", []() -> BaseClass* { return new DerivedClass1(); });
     m.def("return_class_2", []() -> BaseClass* { return new DerivedClass2(); });
     m.def("return_class_n", [](int n) -> BaseClass* {
         if (n == 1) return new DerivedClass1();
         if (n == 2) return new DerivedClass2();
         return new BaseClass();
     });
     m.def("return_none", []() -> BaseClass* { return nullptr; });

     // test_isinstance
     m.def("check_instances", [](py::list l) {
         return py::make_tuple(
             py::isinstance<py::tuple>(l[0]),
             py::isinstance<py::dict>(l[1]),
             py::isinstance<Pet>(l[2]),
             py::isinstance<Pet>(l[3]),
             py::isinstance<Dog>(l[4]),
             py::isinstance<Rabbit>(l[5]),
             py::isinstance<UnregisteredType>(l[6])
         );
     });

     // test_mismatched_holder
     struct MismatchBase1 { };
     struct MismatchDerived1 : MismatchBase1 { };

     struct MismatchBase2 { };
     struct MismatchDerived2 : MismatchBase2 { };

     m.def("mismatched_holder_1", []() {
         auto mod = py::module::import("__main__");
         py::class_<MismatchBase1, std::shared_ptr<MismatchBase1>>(mod, "MismatchBase1");
         py::class_<MismatchDerived1, MismatchBase1>(mod, "MismatchDerived1");
     });
     m.def("mismatched_holder_2", []() {
         auto mod = py::module::import("__main__");
         py::class_<MismatchBase2>(mod, "MismatchBase2");
         py::class_<MismatchDerived2, std::shared_ptr<MismatchDerived2>,
                    MismatchBase2>(mod, "MismatchDerived2");
     });

     // test_override_static
     // #511: problem with inheritance + overwritten def_static
     struct MyBase {
         static std::unique_ptr<MyBase> make() {
             return std::unique_ptr<MyBase>(new MyBase());
         }
     };

     struct MyDerived : MyBase {
         static std::unique_ptr<MyDerived> make() {
             return std::unique_ptr<MyDerived>(new MyDerived());
         }
     };

     py::class_<MyBase>(m, "MyBase")
         .def_static("make", &MyBase::make);

     py::class_<MyDerived, MyBase>(m, "MyDerived")
         .def_static("make", &MyDerived::make)
         .def_static("make2", &MyDerived::make);

     // test_implicit_conversion_life_support
     struct ConvertibleFromUserType {
         int i;

         ConvertibleFromUserType(UserType u) : i(u.value()) { }
     };

     py::class_<ConvertibleFromUserType>(m, "AcceptsUserType")
         .def(py::init<UserType>());
     py::implicitly_convertible<UserType, ConvertibleFromUserType>();

     m.def("implicitly_convert_argument", [](const ConvertibleFromUserType &r) { return r.i; });
     m.def("implicitly_convert_variable", [](py::object o) {
         // `o` is `UserType` and `r` is a reference to a temporary created by implicit
         // conversion. This is valid when called inside a bound function because the temp
         // object is attached to the same life support system as the arguments.
         const auto &r = o.cast<const ConvertibleFromUserType &>();
         return r.i;
     });
     m.add_object("implicitly_convert_variable_fail", [&] {
         auto f = [](PyObject *, PyObject *args) -> PyObject * {
             auto o = py::reinterpret_borrow<py::tuple>(args)[0];
             try { // It should fail here because there is no life support.
                 o.cast<const ConvertibleFromUserType &>();
             } catch (const py::cast_error &e) {
                 return py::str(e.what()).release().ptr();
             }
             return py::str().release().ptr();
         };

         auto def = new PyMethodDef{"f", f, METH_VARARGS, nullptr};
         return py::reinterpret_steal<py::object>(PyCFunction_NewEx(def, nullptr, m.ptr()));
     }());

     // test_operator_new_delete
     struct HasOpNewDel {
         std::uint64_t i;
         static void *operator new(size_t s) { py::print("A new", s); return ::operator new(s); }
         static void *operator new(size_t s, void *ptr) { py::print("A placement-new", s); return ptr; }
         static void operator delete(void *p) { py::print("A delete"); return ::operator delete(p); }
     };
     struct HasOpNewDelSize {
         std::uint32_t i;
         static void *operator new(size_t s) { py::print("B new", s); return ::operator new(s); }
         static void *operator new(size_t s, void *ptr) { py::print("B placement-new", s); return ptr; }
         static void operator delete(void *p, size_t s) { py::print("B delete", s); return ::operator delete(p); }
     };
     struct AliasedHasOpNewDelSize {
         std::uint64_t i;
         static void *operator new(size_t s) { py::print("C new", s); return ::operator new(s); }
         static void *operator new(size_t s, void *ptr) { py::print("C placement-new", s); return ptr; }
         static void operator delete(void *p, size_t s) { py::print("C delete", s); return ::operator delete(p); }
         virtual ~AliasedHasOpNewDelSize() = default;
     };
     struct PyAliasedHasOpNewDelSize : AliasedHasOpNewDelSize {
         PyAliasedHasOpNewDelSize() = default;
         PyAliasedHasOpNewDelSize(int) { }
         std::uint64_t j;
     };
     struct HasOpNewDelBoth {
         std::uint32_t i[8];
         static void *operator new(size_t s) { py::print("D new", s); return ::operator new(s); }
         static void *operator new(size_t s, void *ptr) { py::print("D placement-new", s); return ptr; }
         static void operator delete(void *p) { py::print("D delete"); return ::operator delete(p); }
         static void operator delete(void *p, size_t s) { py::print("D wrong delete", s); return ::operator delete(p); }
     };
     py::class_<HasOpNewDel>(m, "HasOpNewDel").def(py::init<>());
     py::class_<HasOpNewDelSize>(m, "HasOpNewDelSize").def(py::init<>());
     py::class_<HasOpNewDelBoth>(m, "HasOpNewDelBoth").def(py::init<>());
     py::class_<AliasedHasOpNewDelSize, PyAliasedHasOpNewDelSize> aliased(m, "AliasedHasOpNewDelSize");
     aliased.def(py::init<>());
     aliased.attr("size_noalias") = py::int_(sizeof(AliasedHasOpNewDelSize));
     aliased.attr("size_alias") = py::int_(sizeof(PyAliasedHasOpNewDelSize));

     // This test is actually part of test_local_bindings (test_duplicate_local), but we need a
     // definition in a different compilation unit within the same module:
     bind_local<LocalExternal, 17>(m, "LocalExternal", py::module_local());

     // test_bind_protected_functions
     class ProtectedA {
     protected:
         int foo() const { return value; }

     private:
         int value = 42;
     };

     class PublicistA : public ProtectedA {
     public:
         using ProtectedA::foo;
     };

     py::class_<ProtectedA>(m, "ProtectedA")
         .def(py::init<>())
 #if !defined(_MSC_VER) || _MSC_VER >= 1910
         .def("foo", &PublicistA::foo);
 #else
         .def("foo", static_cast<int (ProtectedA::*)() const>(&PublicistA::foo));
 #endif

     class ProtectedB {
     public:
         virtual ~ProtectedB() = default;

     protected:
         virtual int foo() const { return value; }

     private:
         int value = 42;
     };

     class TrampolineB : public ProtectedB {
     public:
         int foo() const override { PYBIND11_OVERLOAD(int, ProtectedB, foo, ); }
     };

     class PublicistB : public ProtectedB {
     public:
         using ProtectedB::foo;
     };

     py::class_<ProtectedB, TrampolineB>(m, "ProtectedB")
         .def(py::init<>())
 #if !defined(_MSC_VER) || _MSC_VER >= 1910
         .def("foo", &PublicistB::foo);
 #else
         .def("foo", static_cast<int (ProtectedB::*)() const>(&PublicistB::foo));
 #endif

     // test_brace_initialization
     struct BraceInitialization {
         int field1;
         std::string field2;
     };

     py::class_<BraceInitialization>(m, "BraceInitialization")
         .def(py::init<int, const std::string &>())
         .def_readwrite("field1", &BraceInitialization::field1)
         .def_readwrite("field2", &BraceInitialization::field2);
     // We *don't* want to construct using braces when the given constructor argument maps to a
     // constructor, because brace initialization could go to the wrong place (in particular when
     // there is also an `initializer_list<T>`-accept constructor):
     py::class_<NoBraceInitialization>(m, "NoBraceInitialization")
         .def(py::init<std::vector<int>>())
         .def_readonly("vec", &NoBraceInitialization::vec);

     // test_reentrant_implicit_conversion_failure
     // #1035: issue with runaway reentrant implicit conversion
     struct BogusImplicitConversion {
         BogusImplicitConversion(const BogusImplicitConversion &) { }
     };

     py::class_<BogusImplicitConversion>(m, "BogusImplicitConversion")
         .def(py::init<const BogusImplicitConversion &>());

     py::implicitly_convertible<int, BogusImplicitConversion>();

     // test_qualname
     // #1166: nested class docstring doesn't show nested name
     // Also related: tests that __qualname__ is set properly
     struct NestBase {};
     struct Nested {};
     py::class_<NestBase> base(m, "NestBase");
     base.def(py::init<>());
     py::class_<Nested>(base, "Nested")
         .def(py::init<>())
         .def("fn", [](Nested &, int, NestBase &, Nested &) {})
         .def("fa", [](Nested &, int, NestBase &, Nested &) {},
                 "a"_a, "b"_a, "c"_a);
     base.def("g", [](NestBase &, Nested &) {});
     base.def("h", []() { return NestBase(); });

     // test_error_after_conversion
     // The second-pass path through dispatcher() previously didn't
     // remember which overload was used, and would crash trying to
     // generate a useful error message

     struct NotRegistered {};
     struct StringWrapper { std::string str; };
     m.def("test_error_after_conversions", [](int) {});
     m.def("test_error_after_conversions",
           [](StringWrapper) -> NotRegistered { return {}; });
     py::class_<StringWrapper>(m, "StringWrapper").def(py::init<std::string>());
     py::implicitly_convertible<std::string, StringWrapper>();

     #if defined(PYBIND11_CPP17)
         struct alignas(1024) Aligned {
             std::uintptr_t ptr() const { return (uintptr_t) this; }
         };
         py::class_<Aligned>(m, "Aligned")
             .def(py::init<>())
             .def("ptr", &Aligned::ptr);
     #endif
 }

 template <int N> class BreaksBase { public: virtual ~BreaksBase() = default; };
 template <int N> class BreaksTramp : public BreaksBase<N> {};
 // These should all compile just fine:
 typedef py::class_<BreaksBase<1>, std::unique_ptr<BreaksBase<1>>, BreaksTramp<1>> DoesntBreak1;
 typedef py::class_<BreaksBase<2>, BreaksTramp<2>, std::unique_ptr<BreaksBase<2>>> DoesntBreak2;
 typedef py::class_<BreaksBase<3>, std::unique_ptr<BreaksBase<3>>> DoesntBreak3;
 typedef py::class_<BreaksBase<4>, BreaksTramp<4>> DoesntBreak4;
 typedef py::class_<BreaksBase<5>> DoesntBreak5;
 typedef py::class_<BreaksBase<6>, std::shared_ptr<BreaksBase<6>>, BreaksTramp<6>> DoesntBreak6;
 typedef py::class_<BreaksBase<7>, BreaksTramp<7>, std::shared_ptr<BreaksBase<7>>> DoesntBreak7;
 typedef py::class_<BreaksBase<8>, std::shared_ptr<BreaksBase<8>>> DoesntBreak8;
 #define CHECK_BASE(N) static_assert(std::is_same<typename DoesntBreak##N::type, BreaksBase<N>>::value, \
         "DoesntBreak" #N " has wrong type!")
 CHECK_BASE(1); CHECK_BASE(2); CHECK_BASE(3); CHECK_BASE(4); CHECK_BASE(5); CHECK_BASE(6); CHECK_BASE(7); CHECK_BASE(8);
 #define CHECK_ALIAS(N) static_assert(DoesntBreak##N::has_alias && std::is_same<typename DoesntBreak##N::type_alias, BreaksTramp<N>>::value, \
         "DoesntBreak" #N " has wrong type_alias!")
 #define CHECK_NOALIAS(N) static_assert(!DoesntBreak##N::has_alias && std::is_void<typename DoesntBreak##N::type_alias>::value, \
         "DoesntBreak" #N " has type alias, but shouldn't!")
 CHECK_ALIAS(1); CHECK_ALIAS(2); CHECK_NOALIAS(3); CHECK_ALIAS(4); CHECK_NOALIAS(5); CHECK_ALIAS(6); CHECK_ALIAS(7); CHECK_NOALIAS(8);
 #define CHECK_HOLDER(N, TYPE) static_assert(std::is_same<typename DoesntBreak##N::holder_type, std::TYPE##_ptr<BreaksBase<N>>>::value, \
         "DoesntBreak" #N " has wrong holder_type!")
 CHECK_HOLDER(1, unique); CHECK_HOLDER(2, unique); CHECK_HOLDER(3, unique); CHECK_HOLDER(4, unique); CHECK_HOLDER(5, unique);
 CHECK_HOLDER(6, shared); CHECK_HOLDER(7, shared); CHECK_HOLDER(8, shared);

 // There's no nice way to test that these fail because they fail to compile; leave them here,
 // though, so that they can be manually tested by uncommenting them (and seeing that compilation
 // failures occurs).

 // We have to actually look into the type: the typedef alone isn't enough to instantiate the type:
 #define CHECK_BROKEN(N) static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-N>>::value, \
         "Breaks1 has wrong type!");

 //// Two holder classes:
 //typedef py::class_<BreaksBase<-1>, std::unique_ptr<BreaksBase<-1>>, std::unique_ptr<BreaksBase<-1>>> Breaks1;
 //CHECK_BROKEN(1);
 //// Two aliases:
 //typedef py::class_<BreaksBase<-2>, BreaksTramp<-2>, BreaksTramp<-2>> Breaks2;
 //CHECK_BROKEN(2);
 //// Holder + 2 aliases
 //typedef py::class_<BreaksBase<-3>, std::unique_ptr<BreaksBase<-3>>, BreaksTramp<-3>, BreaksTramp<-3>> Breaks3;
 //CHECK_BROKEN(3);
 //// Alias + 2 holders
 //typedef py::class_<BreaksBase<-4>, std::unique_ptr<BreaksBase<-4>>, BreaksTramp<-4>, std::shared_ptr<BreaksBase<-4>>> Breaks4;
 //CHECK_BROKEN(4);
 //// Invalid option (not a subclass or holder)
 //typedef py::class_<BreaksBase<-5>, BreaksTramp<-4>> Breaks5;
 //CHECK_BROKEN(5);
 //// Invalid option: multiple inheritance not supported:
 //template <> struct BreaksBase<-8> : BreaksBase<-6>, BreaksBase<-7> {};
 //typedef py::class_<BreaksBase<-8>, BreaksBase<-6>, BreaksBase<-7>> Breaks8;
 //CHECK_BROKEN(8);
	/*
	tests/test_class.cpp -- test py::class_ definitions and basic functionality

	Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>

	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 "constructor_stats.h"
	#include "local_bindings.h"
	#include <pybind11/stl.h>

	#if defined(_MSC_VER)
	# pragma warning(disable: 4324) // warning C4324: structure was padded due to alignment specifier
	#endif

	// test_brace_initialization
	struct NoBraceInitialization {
	NoBraceInitialization(std::vector<int> v) : vec{std::move(v)} {}
	template <typename T>
	NoBraceInitialization(std::initializer_list<T> l) : vec(l) {}

	std::vector<int> vec;
	};

	TEST_SUBMODULE(class_, m) {
	// test_instance
	struct NoConstructor {
	NoConstructor() = default;
	NoConstructor(const NoConstructor &) = default;
	NoConstructor(NoConstructor &&) = default;
	static NoConstructor *new_instance() {
	auto *ptr = new NoConstructor();
	print_created(ptr, "via new_instance");
	return ptr;
	}
	~NoConstructor() { print_destroyed(this); }
	};

	py::class_<NoConstructor>(m, "NoConstructor")
	.def_static("new_instance", &NoConstructor::new_instance, "Return an instance");

	// test_inheritance
	class Pet {
	public:
	Pet(const std::string &name, const std::string &species)
	: m_name(name), m_species(species) {}
	std::string name() const { return m_name; }
	std::string species() const { return m_species; }
	private:
	std::string m_name;
	std::string m_species;
	};

	class Dog : public Pet {
	public:
	Dog(const std::string &name) : Pet(name, "dog") {}
	std::string bark() const { return "Woof!"; }
	};

	class Rabbit : public Pet {
	public:
	Rabbit(const std::string &name) : Pet(name, "parrot") {}
	};

	class Hamster : public Pet {
	public:
	Hamster(const std::string &name) : Pet(name, "rodent") {}
	};

	class Chimera : public Pet {
	Chimera() : Pet("Kimmy", "chimera") {}
	};

	py::class_<Pet> pet_class(m, "Pet");
	pet_class
	.def(py::init<std::string, std::string>())
	.def("name", &Pet::name)
	.def("species", &Pet::species);

	/* One way of declaring a subclass relationship: reference parent's class_ object */
	py::class_<Dog>(m, "Dog", pet_class)
	.def(py::init<std::string>());

	/* Another way of declaring a subclass relationship: reference parent's C++ type */
	py::class_<Rabbit, Pet>(m, "Rabbit")
	.def(py::init<std::string>());

	/* And another: list parent in class template arguments */
	py::class_<Hamster, Pet>(m, "Hamster")
	.def(py::init<std::string>());

	/* Constructors are not inherited by default */
	py::class_<Chimera, Pet>(m, "Chimera");

	m.def("pet_name_species", [](const Pet &pet) { return pet.name() + " is a " + pet.species(); });
	m.def("dog_bark", [](const Dog &dog) { return dog.bark(); });

	// test_automatic_upcasting
	struct BaseClass {
	BaseClass() = default;
	BaseClass(const BaseClass &) = default;
	BaseClass(BaseClass &&) = default;
	virtual ~BaseClass() {}
	};
	struct DerivedClass1 : BaseClass { };
	struct DerivedClass2 : BaseClass { };

	py::class_<BaseClass>(m, "BaseClass").def(py::init<>());
	py::class_<DerivedClass1>(m, "DerivedClass1").def(py::init<>());
	py::class_<DerivedClass2>(m, "DerivedClass2").def(py::init<>());

	m.def("return_class_1", []() -> BaseClass* { return new DerivedClass1(); });
	m.def("return_class_2", []() -> BaseClass* { return new DerivedClass2(); });
	m.def("return_class_n", [](int n) -> BaseClass* {
	if (n == 1) return new DerivedClass1();
	if (n == 2) return new DerivedClass2();
	return new BaseClass();
	});
	m.def("return_none", []() -> BaseClass* { return nullptr; });

	// test_isinstance
	m.def("check_instances", [](py::list l) {
	return py::make_tuple(
	py::isinstance<py::tuple>(l[0]),
	py::isinstance<py::dict>(l[1]),
	py::isinstance<Pet>(l[2]),
	py::isinstance<Pet>(l[3]),
	py::isinstance<Dog>(l[4]),
	py::isinstance<Rabbit>(l[5]),
	py::isinstance<UnregisteredType>(l[6])
	);
	});

	// test_mismatched_holder
	struct MismatchBase1 { };
	struct MismatchDerived1 : MismatchBase1 { };

	struct MismatchBase2 { };
	struct MismatchDerived2 : MismatchBase2 { };

	m.def("mismatched_holder_1", []() {
	auto mod = py::module::import("__main__");
	py::class_<MismatchBase1, std::shared_ptr<MismatchBase1>>(mod, "MismatchBase1");
	py::class_<MismatchDerived1, MismatchBase1>(mod, "MismatchDerived1");
	});
	m.def("mismatched_holder_2", []() {
	auto mod = py::module::import("__main__");
	py::class_<MismatchBase2>(mod, "MismatchBase2");
	py::class_<MismatchDerived2, std::shared_ptr<MismatchDerived2>,
	MismatchBase2>(mod, "MismatchDerived2");
	});

	// test_override_static
	// #511: problem with inheritance + overwritten def_static
	struct MyBase {
	static std::unique_ptr<MyBase> make() {
	return std::unique_ptr<MyBase>(new MyBase());
	}
	};

	struct MyDerived : MyBase {
	static std::unique_ptr<MyDerived> make() {
	return std::unique_ptr<MyDerived>(new MyDerived());
	}
	};

	py::class_<MyBase>(m, "MyBase")
	.def_static("make", &MyBase::make);

	py::class_<MyDerived, MyBase>(m, "MyDerived")
	.def_static("make", &MyDerived::make)
	.def_static("make2", &MyDerived::make);

	// test_implicit_conversion_life_support
	struct ConvertibleFromUserType {
	int i;

	ConvertibleFromUserType(UserType u) : i(u.value()) { }
	};

	py::class_<ConvertibleFromUserType>(m, "AcceptsUserType")
	.def(py::init<UserType>());
	py::implicitly_convertible<UserType, ConvertibleFromUserType>();

	m.def("implicitly_convert_argument", [](const ConvertibleFromUserType &r) { return r.i; });
	m.def("implicitly_convert_variable", [](py::object o) {
	// `o` is `UserType` and `r` is a reference to a temporary created by implicit
	// conversion. This is valid when called inside a bound function because the temp
	// object is attached to the same life support system as the arguments.
	const auto &r = o.cast<const ConvertibleFromUserType &>();
	return r.i;
	});
	m.add_object("implicitly_convert_variable_fail", [&] {
	auto f = [](PyObject , PyObject args) -> PyObject * {
	auto o = py::reinterpret_borrow<py::tuple>(args)[0];
	try { // It should fail here because there is no life support.
	o.cast<const ConvertibleFromUserType &>();
	} catch (const py::cast_error &e) {
	return py::str(e.what()).release().ptr();
	}
	return py::str().release().ptr();
	};

	auto def = new PyMethodDef{"f", f, METH_VARARGS, nullptr};
	return py::reinterpret_steal<py::object>(PyCFunction_NewEx(def, nullptr, m.ptr()));
	}());

	// test_operator_new_delete
	struct HasOpNewDel {
	std::uint64_t i;
	static void *operator new(size_t s) { py::print("A new", s); return ::operator new(s); }
	static void operator new(size_t s, void ptr) { py::print("A placement-new", s); return ptr; }
	static void operator delete(void *p) { py::print("A delete"); return ::operator delete(p); }
	};
	struct HasOpNewDelSize {
	std::uint32_t i;
	static void *operator new(size_t s) { py::print("B new", s); return ::operator new(s); }
	static void operator new(size_t s, void ptr) { py::print("B placement-new", s); return ptr; }
	static void operator delete(void *p, size_t s) { py::print("B delete", s); return ::operator delete(p); }
	};
	struct AliasedHasOpNewDelSize {
	std::uint64_t i;
	static void *operator new(size_t s) { py::print("C new", s); return ::operator new(s); }
	static void operator new(size_t s, void ptr) { py::print("C placement-new", s); return ptr; }
	static void operator delete(void *p, size_t s) { py::print("C delete", s); return ::operator delete(p); }
	virtual ~AliasedHasOpNewDelSize() = default;
	};
	struct PyAliasedHasOpNewDelSize : AliasedHasOpNewDelSize {
	PyAliasedHasOpNewDelSize() = default;
	PyAliasedHasOpNewDelSize(int) { }
	std::uint64_t j;
	};
	struct HasOpNewDelBoth {
	std::uint32_t i[8];
	static void *operator new(size_t s) { py::print("D new", s); return ::operator new(s); }
	static void operator new(size_t s, void ptr) { py::print("D placement-new", s); return ptr; }
	static void operator delete(void *p) { py::print("D delete"); return ::operator delete(p); }
	static void operator delete(void *p, size_t s) { py::print("D wrong delete", s); return ::operator delete(p); }
	};
	py::class_<HasOpNewDel>(m, "HasOpNewDel").def(py::init<>());
	py::class_<HasOpNewDelSize>(m, "HasOpNewDelSize").def(py::init<>());
	py::class_<HasOpNewDelBoth>(m, "HasOpNewDelBoth").def(py::init<>());
	py::class_<AliasedHasOpNewDelSize, PyAliasedHasOpNewDelSize> aliased(m, "AliasedHasOpNewDelSize");
	aliased.def(py::init<>());
	aliased.attr("size_noalias") = py::int_(sizeof(AliasedHasOpNewDelSize));
	aliased.attr("size_alias") = py::int_(sizeof(PyAliasedHasOpNewDelSize));

	// This test is actually part of test_local_bindings (test_duplicate_local), but we need a
	// definition in a different compilation unit within the same module:
	bind_local<LocalExternal, 17>(m, "LocalExternal", py::module_local());

	// test_bind_protected_functions
	class ProtectedA {
	protected:
	int foo() const { return value; }

	private:
	int value = 42;
	};

	class PublicistA : public ProtectedA {
	public:
	using ProtectedA::foo;
	};

	py::class_<ProtectedA>(m, "ProtectedA")
	.def(py::init<>())
	#if !defined(_MSC_VER) \|\| _MSC_VER >= 1910
	.def("foo", &PublicistA::foo);
	#else
	.def("foo", static_cast<int (ProtectedA::*)() const>(&PublicistA::foo));
	#endif

	class ProtectedB {
	public:
	virtual ~ProtectedB() = default;

	protected:
	virtual int foo() const { return value; }

	private:
	int value = 42;
	};

	class TrampolineB : public ProtectedB {
	public:
	int foo() const override { PYBIND11_OVERLOAD(int, ProtectedB, foo, ); }
	};

	class PublicistB : public ProtectedB {
	public:
	using ProtectedB::foo;
	};

	py::class_<ProtectedB, TrampolineB>(m, "ProtectedB")
	.def(py::init<>())
	#if !defined(_MSC_VER) \|\| _MSC_VER >= 1910
	.def("foo", &PublicistB::foo);
	#else
	.def("foo", static_cast<int (ProtectedB::*)() const>(&PublicistB::foo));
	#endif

	// test_brace_initialization
	struct BraceInitialization {
	int field1;
	std::string field2;
	};

	py::class_<BraceInitialization>(m, "BraceInitialization")
	.def(py::init<int, const std::string &>())
	.def_readwrite("field1", &BraceInitialization::field1)
	.def_readwrite("field2", &BraceInitialization::field2);
	// We don't want to construct using braces when the given constructor argument maps to a
	// constructor, because brace initialization could go to the wrong place (in particular when
	// there is also an `initializer_list<T>`-accept constructor):
	py::class_<NoBraceInitialization>(m, "NoBraceInitialization")
	.def(py::init<std::vector<int>>())
	.def_readonly("vec", &NoBraceInitialization::vec);

	// test_reentrant_implicit_conversion_failure
	// #1035: issue with runaway reentrant implicit conversion
	struct BogusImplicitConversion {
	BogusImplicitConversion(const BogusImplicitConversion &) { }
	};

	py::class_<BogusImplicitConversion>(m, "BogusImplicitConversion")
	.def(py::init<const BogusImplicitConversion &>());

	py::implicitly_convertible<int, BogusImplicitConversion>();

	// test_qualname
	// #1166: nested class docstring doesn't show nested name
	// Also related: tests that __qualname__ is set properly
	struct NestBase {};
	struct Nested {};
	py::class_<NestBase> base(m, "NestBase");
	base.def(py::init<>());
	py::class_<Nested>(base, "Nested")
	.def(py::init<>())
	.def("fn", [](Nested &, int, NestBase &, Nested &) {})
	.def("fa", [](Nested &, int, NestBase &, Nested &) {},
	"a"_a, "b"_a, "c"_a);
	base.def("g", [](NestBase &, Nested &) {});
	base.def("h", []() { return NestBase(); });

	// test_error_after_conversion
	// The second-pass path through dispatcher() previously didn't
	// remember which overload was used, and would crash trying to
	// generate a useful error message

	struct NotRegistered {};
	struct StringWrapper { std::string str; };
	m.def("test_error_after_conversions", [](int) {});
	m.def("test_error_after_conversions",
	[](StringWrapper) -> NotRegistered { return {}; });
	py::class_<StringWrapper>(m, "StringWrapper").def(py::init<std::string>());
	py::implicitly_convertible<std::string, StringWrapper>();

	#if defined(PYBIND11_CPP17)
	struct alignas(1024) Aligned {
	std::uintptr_t ptr() const { return (uintptr_t) this; }
	};
	py::class_<Aligned>(m, "Aligned")
	.def(py::init<>())
	.def("ptr", &Aligned::ptr);
	#endif
	}

	template <int N> class BreaksBase { public: virtual ~BreaksBase() = default; };
	template <int N> class BreaksTramp : public BreaksBase<N> {};
	// These should all compile just fine:
	typedef py::class_<BreaksBase<1>, std::unique_ptr<BreaksBase<1>>, BreaksTramp<1>> DoesntBreak1;
	typedef py::class_<BreaksBase<2>, BreaksTramp<2>, std::unique_ptr<BreaksBase<2>>> DoesntBreak2;
	typedef py::class_<BreaksBase<3>, std::unique_ptr<BreaksBase<3>>> DoesntBreak3;
	typedef py::class_<BreaksBase<4>, BreaksTramp<4>> DoesntBreak4;
	typedef py::class_<BreaksBase<5>> DoesntBreak5;
	typedef py::class_<BreaksBase<6>, std::shared_ptr<BreaksBase<6>>, BreaksTramp<6>> DoesntBreak6;
	typedef py::class_<BreaksBase<7>, BreaksTramp<7>, std::shared_ptr<BreaksBase<7>>> DoesntBreak7;
	typedef py::class_<BreaksBase<8>, std::shared_ptr<BreaksBase<8>>> DoesntBreak8;
	#define CHECK_BASE(N) static_assert(std::is_same<typename DoesntBreak##N::type, BreaksBase<N>>::value, \
	"DoesntBreak" #N " has wrong type!")
	CHECK_BASE(1); CHECK_BASE(2); CHECK_BASE(3); CHECK_BASE(4); CHECK_BASE(5); CHECK_BASE(6); CHECK_BASE(7); CHECK_BASE(8);
	#define CHECK_ALIAS(N) static_assert(DoesntBreak##N::has_alias && std::is_same<typename DoesntBreak##N::type_alias, BreaksTramp<N>>::value, \
	"DoesntBreak" #N " has wrong type_alias!")
	#define CHECK_NOALIAS(N) static_assert(!DoesntBreak##N::has_alias && std::is_void<typename DoesntBreak##N::type_alias>::value, \
	"DoesntBreak" #N " has type alias, but shouldn't!")
	CHECK_ALIAS(1); CHECK_ALIAS(2); CHECK_NOALIAS(3); CHECK_ALIAS(4); CHECK_NOALIAS(5); CHECK_ALIAS(6); CHECK_ALIAS(7); CHECK_NOALIAS(8);
	#define CHECK_HOLDER(N, TYPE) static_assert(std::is_same<typename DoesntBreak##N::holder_type, std::TYPE##_ptr<BreaksBase<N>>>::value, \
	"DoesntBreak" #N " has wrong holder_type!")
	CHECK_HOLDER(1, unique); CHECK_HOLDER(2, unique); CHECK_HOLDER(3, unique); CHECK_HOLDER(4, unique); CHECK_HOLDER(5, unique);
	CHECK_HOLDER(6, shared); CHECK_HOLDER(7, shared); CHECK_HOLDER(8, shared);

	// There's no nice way to test that these fail because they fail to compile; leave them here,
	// though, so that they can be manually tested by uncommenting them (and seeing that compilation
	// failures occurs).

	// We have to actually look into the type: the typedef alone isn't enough to instantiate the type:
	#define CHECK_BROKEN(N) static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-N>>::value, \
	"Breaks1 has wrong type!");

	//// Two holder classes:
	//typedef py::class_<BreaksBase<-1>, std::unique_ptr<BreaksBase<-1>>, std::unique_ptr<BreaksBase<-1>>> Breaks1;
	//CHECK_BROKEN(1);
	//// Two aliases:
	//typedef py::class_<BreaksBase<-2>, BreaksTramp<-2>, BreaksTramp<-2>> Breaks2;
	//CHECK_BROKEN(2);
	//// Holder + 2 aliases
	//typedef py::class_<BreaksBase<-3>, std::unique_ptr<BreaksBase<-3>>, BreaksTramp<-3>, BreaksTramp<-3>> Breaks3;
	//CHECK_BROKEN(3);
	//// Alias + 2 holders
	//typedef py::class_<BreaksBase<-4>, std::unique_ptr<BreaksBase<-4>>, BreaksTramp<-4>, std::shared_ptr<BreaksBase<-4>>> Breaks4;
	//CHECK_BROKEN(4);
	//// Invalid option (not a subclass or holder)
	//typedef py::class_<BreaksBase<-5>, BreaksTramp<-4>> Breaks5;
	//CHECK_BROKEN(5);
	//// Invalid option: multiple inheritance not supported:
	//template <> struct BreaksBase<-8> : BreaksBase<-6>, BreaksBase<-7> {};
	//typedef py::class_<BreaksBase<-8>, BreaksBase<-6>, BreaksBase<-7>> Breaks8;
	//CHECK_BROKEN(8);