| /* |
| 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<>()); |
| |
| }; |
| |
| |
| test_initializer virtual_functions([](py::module &m) { |
| /* Important: indicate the trampoline class PyExampleVirt using the third |
| argument to py::class_. The second argument with the unique pointer |
| is simply the default holder type used by pybind11. */ |
| 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); |
| }); |