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Diffstat (limited to 'ext/pybind11/tests/test_virtual_functions.cpp')
| -rw-r--r-- | ext/pybind11/tests/test_virtual_functions.cpp | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/ext/pybind11/tests/test_virtual_functions.cpp b/ext/pybind11/tests/test_virtual_functions.cpp new file mode 100644 index 000000000..0f8ed2afb --- /dev/null +++ b/ext/pybind11/tests/test_virtual_functions.cpp @@ -0,0 +1,347 @@ +/* + 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); +}); |