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				| /* | |
|     tests/test_virtual_functions.cpp -- overriding virtual functions from Python | |
|  | |
|     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 <pybind11/functional.h> | |
|  | |
| /* This is an example class that we'll want to be able to extend from Python */ | |
| class ExampleVirt  { | |
| public: | |
|     ExampleVirt(int state) : state(state) { print_created(this, state); } | |
|     ExampleVirt(const ExampleVirt &e) : state(e.state) { print_copy_created(this); } | |
|     ExampleVirt(ExampleVirt &&e) : state(e.state) { print_move_created(this); e.state = 0; } | |
|     ~ExampleVirt() { print_destroyed(this); } | |
| 
 | |
|     virtual int run(int value) { | |
|         py::print("Original implementation of " | |
|                   "ExampleVirt::run(state={}, value={}, str1={}, str2={})"_s.format(state, value, get_string1(), *get_string2())); | |
|         return state + value; | |
|     } | |
| 
 | |
|     virtual bool run_bool() = 0; | |
|     virtual void pure_virtual() = 0; | |
| 
 | |
|     // Returning a reference/pointer to a type converted from python (numbers, strings, etc.) is a | |
|     // bit trickier, because the actual int& or std::string& or whatever only exists temporarily, so | |
|     // we have to handle it specially in the trampoline class (see below). | |
|     virtual const std::string &get_string1() { return str1; } | |
|     virtual const std::string *get_string2() { return &str2; } | |
| 
 | |
| private: | |
|     int state; | |
|     const std::string str1{"default1"}, str2{"default2"}; | |
| }; | |
| 
 | |
| /* This is a wrapper class that must be generated */ | |
| class PyExampleVirt : public ExampleVirt { | |
| public: | |
|     using ExampleVirt::ExampleVirt; /* Inherit constructors */ | |
| 
 | |
|     int run(int value) override { | |
|         /* Generate wrapping code that enables native function overloading */ | |
|         PYBIND11_OVERLOAD( | |
|             int,         /* Return type */ | |
|             ExampleVirt, /* Parent class */ | |
|             run,         /* Name of function */ | |
|             value        /* Argument(s) */ | |
|         ); | |
|     } | |
| 
 | |
|     bool run_bool() override { | |
|         PYBIND11_OVERLOAD_PURE( | |
|             bool,         /* Return type */ | |
|             ExampleVirt,  /* Parent class */ | |
|             run_bool,     /* Name of function */ | |
|                           /* This function has no arguments. The trailing comma | |
|                              in the previous line is needed for some compilers */ | |
|         ); | |
|     } | |
| 
 | |
|     void pure_virtual() override { | |
|         PYBIND11_OVERLOAD_PURE( | |
|             void,         /* Return type */ | |
|             ExampleVirt,  /* Parent class */ | |
|             pure_virtual, /* Name of function */ | |
|                           /* This function has no arguments. The trailing comma | |
|                              in the previous line is needed for some compilers */ | |
|         ); | |
|     } | |
| 
 | |
|     // We can return reference types for compatibility with C++ virtual interfaces that do so, but | |
|     // note they have some significant limitations (see the documentation). | |
|     const std::string &get_string1() override { | |
|         PYBIND11_OVERLOAD( | |
|             const std::string &, /* Return type */ | |
|             ExampleVirt,         /* Parent class */ | |
|             get_string1,         /* Name of function */ | |
|                                  /* (no arguments) */ | |
|         ); | |
|     } | |
| 
 | |
|     const std::string *get_string2() override { | |
|         PYBIND11_OVERLOAD( | |
|             const std::string *, /* Return type */ | |
|             ExampleVirt,         /* Parent class */ | |
|             get_string2,         /* Name of function */ | |
|                                  /* (no arguments) */ | |
|         ); | |
|     } | |
| 
 | |
| }; | |
| 
 | |
| class NonCopyable { | |
| public: | |
|     NonCopyable(int a, int b) : value{new int(a*b)} { print_created(this, a, b); } | |
|     NonCopyable(NonCopyable &&o) { value = std::move(o.value); print_move_created(this); } | |
|     NonCopyable(const NonCopyable &) = delete; | |
|     NonCopyable() = delete; | |
|     void operator=(const NonCopyable &) = delete; | |
|     void operator=(NonCopyable &&) = delete; | |
|     std::string get_value() const { | |
|         if (value) return std::to_string(*value); else return "(null)"; | |
|     } | |
|     ~NonCopyable() { print_destroyed(this); } | |
| 
 | |
| private: | |
|     std::unique_ptr<int> value; | |
| }; | |
| 
 | |
| // This is like the above, but is both copy and movable.  In effect this means it should get moved | |
| // when it is not referenced elsewhere, but copied if it is still referenced. | |
| class Movable { | |
| public: | |
|     Movable(int a, int b) : value{a+b} { print_created(this, a, b); } | |
|     Movable(const Movable &m) { value = m.value; print_copy_created(this); } | |
|     Movable(Movable &&m) { value = std::move(m.value); print_move_created(this); } | |
|     std::string get_value() const { return std::to_string(value); } | |
|     ~Movable() { print_destroyed(this); } | |
| private: | |
|     int value; | |
| }; | |
| 
 | |
| class NCVirt { | |
| public: | |
|     virtual NonCopyable get_noncopyable(int a, int b) { return NonCopyable(a, b); } | |
|     virtual Movable get_movable(int a, int b) = 0; | |
| 
 | |
|     std::string print_nc(int a, int b) { return get_noncopyable(a, b).get_value(); } | |
|     std::string print_movable(int a, int b) { return get_movable(a, b).get_value(); } | |
| }; | |
| class NCVirtTrampoline : public NCVirt { | |
| #if !defined(__INTEL_COMPILER) | |
|     NonCopyable get_noncopyable(int a, int b) override { | |
|         PYBIND11_OVERLOAD(NonCopyable, NCVirt, get_noncopyable, a, b); | |
|     } | |
| #endif | |
|     Movable get_movable(int a, int b) override { | |
|         PYBIND11_OVERLOAD_PURE(Movable, NCVirt, get_movable, a, b); | |
|     } | |
| }; | |
| 
 | |
| int runExampleVirt(ExampleVirt *ex, int value) { | |
|     return ex->run(value); | |
| } | |
| 
 | |
| bool runExampleVirtBool(ExampleVirt* ex) { | |
|     return ex->run_bool(); | |
| } | |
| 
 | |
| void runExampleVirtVirtual(ExampleVirt *ex) { | |
|     ex->pure_virtual(); | |
| } | |
| 
 | |
| 
 | |
| // Inheriting virtual methods.  We do two versions here: the repeat-everything version and the | |
| // templated trampoline versions mentioned in docs/advanced.rst. | |
| // | |
| // These base classes are exactly the same, but we technically need distinct | |
| // classes for this example code because we need to be able to bind them | |
| // properly (pybind11, sensibly, doesn't allow us to bind the same C++ class to | |
| // multiple python classes). | |
| class A_Repeat { | |
| #define A_METHODS \ | |
| public: \ | |
|     virtual int unlucky_number() = 0; \ | |
|     virtual std::string say_something(unsigned times) { \ | |
|         std::string s = ""; \ | |
|         for (unsigned i = 0; i < times; ++i) \ | |
|             s += "hi"; \ | |
|         return s; \ | |
|     } \ | |
|     std::string say_everything() { \ | |
|         return say_something(1) + " " + std::to_string(unlucky_number()); \ | |
|     } | |
| A_METHODS | |
| }; | |
| class B_Repeat : public A_Repeat { | |
| #define B_METHODS \ | |
| public: \ | |
|     int unlucky_number() override { return 13; } \ | |
|     std::string say_something(unsigned times) override { \ | |
|         return "B says hi " + std::to_string(times) + " times"; \ | |
|     } \ | |
|     virtual double lucky_number() { return 7.0; } | |
| B_METHODS | |
| }; | |
| class C_Repeat : public B_Repeat { | |
| #define C_METHODS \ | |
| public: \ | |
|     int unlucky_number() override { return 4444; } \ | |
|     double lucky_number() override { return 888; } | |
| C_METHODS | |
| }; | |
| class D_Repeat : public C_Repeat { | |
| #define D_METHODS // Nothing overridden. | |
| D_METHODS | |
| }; | |
| 
 | |
| // Base classes for templated inheritance trampolines.  Identical to the repeat-everything version: | |
| class A_Tpl { A_METHODS }; | |
| class B_Tpl : public A_Tpl { B_METHODS }; | |
| class C_Tpl : public B_Tpl { C_METHODS }; | |
| class D_Tpl : public C_Tpl { D_METHODS }; | |
| 
 | |
| 
 | |
| // Inheritance approach 1: each trampoline gets every virtual method (11 in total) | |
| class PyA_Repeat : public A_Repeat { | |
| public: | |
|     using A_Repeat::A_Repeat; | |
|     int unlucky_number() override { PYBIND11_OVERLOAD_PURE(int, A_Repeat, unlucky_number, ); } | |
|     std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, A_Repeat, say_something, times); } | |
| }; | |
| class PyB_Repeat : public B_Repeat { | |
| public: | |
|     using B_Repeat::B_Repeat; | |
|     int unlucky_number() override { PYBIND11_OVERLOAD(int, B_Repeat, unlucky_number, ); } | |
|     std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, B_Repeat, say_something, times); } | |
|     double lucky_number() override { PYBIND11_OVERLOAD(double, B_Repeat, lucky_number, ); } | |
| }; | |
| class PyC_Repeat : public C_Repeat { | |
| public: | |
|     using C_Repeat::C_Repeat; | |
|     int unlucky_number() override { PYBIND11_OVERLOAD(int, C_Repeat, unlucky_number, ); } | |
|     std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, C_Repeat, say_something, times); } | |
|     double lucky_number() override { PYBIND11_OVERLOAD(double, C_Repeat, lucky_number, ); } | |
| }; | |
| class PyD_Repeat : public D_Repeat { | |
| public: | |
|     using D_Repeat::D_Repeat; | |
|     int unlucky_number() override { PYBIND11_OVERLOAD(int, D_Repeat, unlucky_number, ); } | |
|     std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, D_Repeat, say_something, times); } | |
|     double lucky_number() override { PYBIND11_OVERLOAD(double, D_Repeat, lucky_number, ); } | |
| }; | |
| 
 | |
| // Inheritance approach 2: templated trampoline classes. | |
| // | |
| // Advantages: | |
| // - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one for | |
| //   any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes and 11 | |
| //   methods (repeat). | |
| // - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and can | |
| //   properly inherit constructors. | |
| // | |
| // Disadvantage: | |
| // - the compiler must still generate and compile 14 different methods (more, even, than the 11 | |
| //   required for the repeat approach) instead of the 6 required for MI.  (If there was no pure | |
| //   method (or no pure method override), the number would drop down to the same 11 as the repeat | |
| //   approach). | |
| template <class Base = A_Tpl> | |
| class PyA_Tpl : public Base { | |
| public: | |
|     using Base::Base; // Inherit constructors | |
|     int unlucky_number() override { PYBIND11_OVERLOAD_PURE(int, Base, unlucky_number, ); } | |
|     std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, Base, say_something, times); } | |
| }; | |
| template <class Base = B_Tpl> | |
| class PyB_Tpl : public PyA_Tpl<Base> { | |
| public: | |
|     using PyA_Tpl<Base>::PyA_Tpl; // Inherit constructors (via PyA_Tpl's inherited constructors) | |
|     int unlucky_number() override { PYBIND11_OVERLOAD(int, Base, unlucky_number, ); } | |
|     double lucky_number() override { PYBIND11_OVERLOAD(double, Base, lucky_number, ); } | |
| }; | |
| // Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these (we can | |
| // use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead): | |
| /* | |
| template <class Base = C_Tpl> class PyC_Tpl : public PyB_Tpl<Base> { | |
| public: | |
|     using PyB_Tpl<Base>::PyB_Tpl; | |
| }; | |
| template <class Base = D_Tpl> class PyD_Tpl : public PyC_Tpl<Base> { | |
| public: | |
|     using PyC_Tpl<Base>::PyC_Tpl; | |
| }; | |
| */ | |
| 
 | |
| 
 | |
| void initialize_inherited_virtuals(py::module &m) { | |
|     // Method 1: repeat | |
|     py::class_<A_Repeat, PyA_Repeat>(m, "A_Repeat") | |
|         .def(py::init<>()) | |
|         .def("unlucky_number", &A_Repeat::unlucky_number) | |
|         .def("say_something", &A_Repeat::say_something) | |
|         .def("say_everything", &A_Repeat::say_everything); | |
|     py::class_<B_Repeat, A_Repeat, PyB_Repeat>(m, "B_Repeat") | |
|         .def(py::init<>()) | |
|         .def("lucky_number", &B_Repeat::lucky_number); | |
|     py::class_<C_Repeat, B_Repeat, PyC_Repeat>(m, "C_Repeat") | |
|         .def(py::init<>()); | |
|     py::class_<D_Repeat, C_Repeat, PyD_Repeat>(m, "D_Repeat") | |
|         .def(py::init<>()); | |
| 
 | |
|     // Method 2: Templated trampolines | |
|     py::class_<A_Tpl, PyA_Tpl<>>(m, "A_Tpl") | |
|         .def(py::init<>()) | |
|         .def("unlucky_number", &A_Tpl::unlucky_number) | |
|         .def("say_something", &A_Tpl::say_something) | |
|         .def("say_everything", &A_Tpl::say_everything); | |
|     py::class_<B_Tpl, A_Tpl, PyB_Tpl<>>(m, "B_Tpl") | |
|         .def(py::init<>()) | |
|         .def("lucky_number", &B_Tpl::lucky_number); | |
|     py::class_<C_Tpl, B_Tpl, PyB_Tpl<C_Tpl>>(m, "C_Tpl") | |
|         .def(py::init<>()); | |
|     py::class_<D_Tpl, C_Tpl, PyB_Tpl<D_Tpl>>(m, "D_Tpl") | |
|         .def(py::init<>()); | |
| 
 | |
| }; | |
| 
 | |
| struct Base { | |
|     /* for some reason MSVC2015 can't compile this if the function is pure virtual */ | |
|     virtual std::string dispatch() const { return {}; }; | |
| }; | |
| 
 | |
| struct DispatchIssue : Base { | |
|     virtual std::string dispatch() const { | |
|         PYBIND11_OVERLOAD_PURE(std::string, Base, dispatch, /* no arguments */); | |
|     } | |
| }; | |
| 
 | |
| TEST_SUBMODULE(virtual_functions, m) { | |
|     py::class_<ExampleVirt, PyExampleVirt>(m, "ExampleVirt") | |
|         .def(py::init<int>()) | |
|         /* Reference original class in function definitions */ | |
|         .def("run", &ExampleVirt::run) | |
|         .def("run_bool", &ExampleVirt::run_bool) | |
|         .def("pure_virtual", &ExampleVirt::pure_virtual); | |
| 
 | |
|     py::class_<NonCopyable>(m, "NonCopyable") | |
|         .def(py::init<int, int>()); | |
| 
 | |
|     py::class_<Movable>(m, "Movable") | |
|         .def(py::init<int, int>()); | |
| 
 | |
| #if !defined(__INTEL_COMPILER) | |
|     py::class_<NCVirt, NCVirtTrampoline>(m, "NCVirt") | |
|         .def(py::init<>()) | |
|         .def("get_noncopyable", &NCVirt::get_noncopyable) | |
|         .def("get_movable", &NCVirt::get_movable) | |
|         .def("print_nc", &NCVirt::print_nc) | |
|         .def("print_movable", &NCVirt::print_movable); | |
| #endif | |
|  | |
|     m.def("runExampleVirt", &runExampleVirt); | |
|     m.def("runExampleVirtBool", &runExampleVirtBool); | |
|     m.def("runExampleVirtVirtual", &runExampleVirtVirtual); | |
| 
 | |
|     m.def("cstats_debug", &ConstructorStats::get<ExampleVirt>); | |
|     initialize_inherited_virtuals(m); | |
| 
 | |
|     // test_alias_delay_initialization1 | |
|     // don't invoke Python dispatch classes by default when instantiating C++ classes | |
|     // that were not extended on the Python side | |
|     struct A { | |
|         virtual ~A() {} | |
|         virtual void f() { py::print("A.f()"); } | |
|     }; | |
| 
 | |
|     struct PyA : A { | |
|         PyA() { py::print("PyA.PyA()"); } | |
|         ~PyA() { py::print("PyA.~PyA()"); } | |
| 
 | |
|         void f() override { | |
|             py::print("PyA.f()"); | |
|             PYBIND11_OVERLOAD(void, A, f); | |
|         } | |
|     }; | |
| 
 | |
|     py::class_<A, PyA>(m, "A") | |
|         .def(py::init<>()) | |
|         .def("f", &A::f); | |
| 
 | |
|     m.def("call_f", [](A *a) { a->f(); }); | |
| 
 | |
|     // test_alias_delay_initialization2 | |
|     // ... unless we explicitly request it, as in this example: | |
|     struct A2 { | |
|         virtual ~A2() {} | |
|         virtual void f() { py::print("A2.f()"); } | |
|     }; | |
| 
 | |
|     struct PyA2 : A2 { | |
|         PyA2() { py::print("PyA2.PyA2()"); } | |
|         ~PyA2() { py::print("PyA2.~PyA2()"); } | |
|         void f() override { | |
|             py::print("PyA2.f()"); | |
|             PYBIND11_OVERLOAD(void, A2, f); | |
|         } | |
|     }; | |
| 
 | |
|     py::class_<A2, PyA2>(m, "A2") | |
|         .def(py::init_alias<>()) | |
|         .def("f", &A2::f); | |
| 
 | |
|     m.def("call_f", [](A2 *a2) { a2->f(); }); | |
| 
 | |
|     // #159: virtual function dispatch has problems with similar-named functions | |
|     py::class_<Base, DispatchIssue>(m, "DispatchIssue") | |
|         .def(py::init<>()) | |
|         .def("dispatch", &Base::dispatch); | |
| 
 | |
|     m.def("dispatch_issue_go", [](const Base * b) { return b->dispatch(); }); | |
| 
 | |
|     // #392/397: overridding reference-returning functions | |
|     class OverrideTest { | |
|     public: | |
|         struct A { std::string value = "hi"; }; | |
|         std::string v; | |
|         A a; | |
|         explicit OverrideTest(const std::string &v) : v{v} {} | |
|         virtual std::string str_value() { return v; } | |
|         virtual std::string &str_ref() { return v; } | |
|         virtual A A_value() { return a; } | |
|         virtual A &A_ref() { return a; } | |
|     }; | |
| 
 | |
|     class PyOverrideTest : public OverrideTest { | |
|     public: | |
|         using OverrideTest::OverrideTest; | |
|         std::string str_value() override { PYBIND11_OVERLOAD(std::string, OverrideTest, str_value); } | |
|         // Not allowed (uncommenting should hit a static_assert failure): we can't get a reference | |
|         // to a python numeric value, since we only copy values in the numeric type caster: | |
| //      std::string &str_ref() override { PYBIND11_OVERLOAD(std::string &, OverrideTest, str_ref); } | |
|         // But we can work around it like this: | |
|     private: | |
|         std::string _tmp; | |
|         std::string str_ref_helper() { PYBIND11_OVERLOAD(std::string, OverrideTest, str_ref); } | |
|     public: | |
|         std::string &str_ref() override { return _tmp = str_ref_helper(); } | |
| 
 | |
|         A A_value() override { PYBIND11_OVERLOAD(A, OverrideTest, A_value); } | |
|         A &A_ref() override { PYBIND11_OVERLOAD(A &, OverrideTest, A_ref); } | |
|     }; | |
| 
 | |
|     py::class_<OverrideTest::A>(m, "OverrideTest_A") | |
|         .def_readwrite("value", &OverrideTest::A::value); | |
|     py::class_<OverrideTest, PyOverrideTest>(m, "OverrideTest") | |
|         .def(py::init<const std::string &>()) | |
|         .def("str_value", &OverrideTest::str_value) | |
| //      .def("str_ref", &OverrideTest::str_ref) | |
|         .def("A_value", &OverrideTest::A_value) | |
|         .def("A_ref", &OverrideTest::A_ref); | |
| }
 |