480 lines
17 KiB
C++
480 lines
17 KiB
C++
/*
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tests/test_virtual_functions.cpp -- overriding virtual functions from Python
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Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
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All rights reserved. Use of this source code is governed by a
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BSD-style license that can be found in the LICENSE file.
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*/
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#include "pybind11_tests.h"
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#include "constructor_stats.h"
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#include <pybind11/functional.h>
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#include <thread>
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/* This is an example class that we'll want to be able to extend from Python */
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class ExampleVirt {
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public:
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ExampleVirt(int state) : state(state) { print_created(this, state); }
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ExampleVirt(const ExampleVirt &e) : state(e.state) { print_copy_created(this); }
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ExampleVirt(ExampleVirt &&e) : state(e.state) { print_move_created(this); e.state = 0; }
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virtual ~ExampleVirt() { print_destroyed(this); }
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virtual int run(int value) {
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py::print("Original implementation of "
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"ExampleVirt::run(state={}, value={}, str1={}, str2={})"_s.format(state, value, get_string1(), *get_string2()));
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return state + value;
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}
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virtual bool run_bool() = 0;
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virtual void pure_virtual() = 0;
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// Returning a reference/pointer to a type converted from python (numbers, strings, etc.) is a
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// bit trickier, because the actual int& or std::string& or whatever only exists temporarily, so
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// we have to handle it specially in the trampoline class (see below).
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virtual const std::string &get_string1() { return str1; }
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virtual const std::string *get_string2() { return &str2; }
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private:
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int state;
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const std::string str1{"default1"}, str2{"default2"};
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};
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/* This is a wrapper class that must be generated */
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class PyExampleVirt : public ExampleVirt {
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public:
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using ExampleVirt::ExampleVirt; /* Inherit constructors */
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int run(int value) override {
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/* Generate wrapping code that enables native function overloading */
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PYBIND11_OVERLOAD(
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int, /* Return type */
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ExampleVirt, /* Parent class */
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run, /* Name of function */
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value /* Argument(s) */
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);
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}
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bool run_bool() override {
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PYBIND11_OVERLOAD_PURE(
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bool, /* Return type */
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ExampleVirt, /* Parent class */
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run_bool, /* Name of function */
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/* This function has no arguments. The trailing comma
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in the previous line is needed for some compilers */
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);
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}
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void pure_virtual() override {
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PYBIND11_OVERLOAD_PURE(
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void, /* Return type */
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ExampleVirt, /* Parent class */
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pure_virtual, /* Name of function */
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/* This function has no arguments. The trailing comma
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in the previous line is needed for some compilers */
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);
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}
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// We can return reference types for compatibility with C++ virtual interfaces that do so, but
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// note they have some significant limitations (see the documentation).
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const std::string &get_string1() override {
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PYBIND11_OVERLOAD(
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const std::string &, /* Return type */
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ExampleVirt, /* Parent class */
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get_string1, /* Name of function */
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/* (no arguments) */
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);
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}
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const std::string *get_string2() override {
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PYBIND11_OVERLOAD(
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const std::string *, /* Return type */
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ExampleVirt, /* Parent class */
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get_string2, /* Name of function */
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/* (no arguments) */
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);
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}
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};
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class NonCopyable {
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public:
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NonCopyable(int a, int b) : value{new int(a*b)} { print_created(this, a, b); }
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NonCopyable(NonCopyable &&o) { value = std::move(o.value); print_move_created(this); }
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NonCopyable(const NonCopyable &) = delete;
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NonCopyable() = delete;
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void operator=(const NonCopyable &) = delete;
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void operator=(NonCopyable &&) = delete;
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std::string get_value() const {
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if (value) return std::to_string(*value); else return "(null)";
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}
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~NonCopyable() { print_destroyed(this); }
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private:
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std::unique_ptr<int> value;
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};
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// This is like the above, but is both copy and movable. In effect this means it should get moved
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// when it is not referenced elsewhere, but copied if it is still referenced.
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class Movable {
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public:
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Movable(int a, int b) : value{a+b} { print_created(this, a, b); }
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Movable(const Movable &m) { value = m.value; print_copy_created(this); }
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Movable(Movable &&m) { value = std::move(m.value); print_move_created(this); }
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std::string get_value() const { return std::to_string(value); }
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~Movable() { print_destroyed(this); }
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private:
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int value;
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};
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class NCVirt {
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public:
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virtual ~NCVirt() { }
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virtual NonCopyable get_noncopyable(int a, int b) { return NonCopyable(a, b); }
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virtual Movable get_movable(int a, int b) = 0;
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std::string print_nc(int a, int b) { return get_noncopyable(a, b).get_value(); }
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std::string print_movable(int a, int b) { return get_movable(a, b).get_value(); }
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};
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class NCVirtTrampoline : public NCVirt {
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#if !defined(__INTEL_COMPILER)
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NonCopyable get_noncopyable(int a, int b) override {
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PYBIND11_OVERLOAD(NonCopyable, NCVirt, get_noncopyable, a, b);
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}
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#endif
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Movable get_movable(int a, int b) override {
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PYBIND11_OVERLOAD_PURE(Movable, NCVirt, get_movable, a, b);
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}
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};
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struct Base {
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/* for some reason MSVC2015 can't compile this if the function is pure virtual */
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virtual std::string dispatch() const { return {}; };
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virtual ~Base() = default;
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};
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struct DispatchIssue : Base {
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virtual std::string dispatch() const {
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PYBIND11_OVERLOAD_PURE(std::string, Base, dispatch, /* no arguments */);
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}
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};
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static void test_gil() {
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{
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py::gil_scoped_acquire lock;
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py::print("1st lock acquired");
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}
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{
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py::gil_scoped_acquire lock;
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py::print("2nd lock acquired");
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}
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}
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static void test_gil_from_thread() {
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py::gil_scoped_release release;
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std::thread t(test_gil);
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t.join();
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}
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// Forward declaration (so that we can put the main tests here; the inherited virtual approaches are
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// rather long).
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void initialize_inherited_virtuals(py::module &m);
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TEST_SUBMODULE(virtual_functions, m) {
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// test_override
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py::class_<ExampleVirt, PyExampleVirt>(m, "ExampleVirt")
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.def(py::init<int>())
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/* Reference original class in function definitions */
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.def("run", &ExampleVirt::run)
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.def("run_bool", &ExampleVirt::run_bool)
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.def("pure_virtual", &ExampleVirt::pure_virtual);
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py::class_<NonCopyable>(m, "NonCopyable")
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.def(py::init<int, int>());
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py::class_<Movable>(m, "Movable")
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.def(py::init<int, int>());
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// test_move_support
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#if !defined(__INTEL_COMPILER)
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py::class_<NCVirt, NCVirtTrampoline>(m, "NCVirt")
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.def(py::init<>())
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.def("get_noncopyable", &NCVirt::get_noncopyable)
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.def("get_movable", &NCVirt::get_movable)
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.def("print_nc", &NCVirt::print_nc)
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.def("print_movable", &NCVirt::print_movable);
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#endif
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m.def("runExampleVirt", [](ExampleVirt *ex, int value) { return ex->run(value); });
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m.def("runExampleVirtBool", [](ExampleVirt* ex) { return ex->run_bool(); });
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m.def("runExampleVirtVirtual", [](ExampleVirt *ex) { ex->pure_virtual(); });
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m.def("cstats_debug", &ConstructorStats::get<ExampleVirt>);
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initialize_inherited_virtuals(m);
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// test_alias_delay_initialization1
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// don't invoke Python dispatch classes by default when instantiating C++ classes
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// that were not extended on the Python side
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struct A {
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virtual ~A() {}
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virtual void f() { py::print("A.f()"); }
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};
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struct PyA : A {
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PyA() { py::print("PyA.PyA()"); }
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~PyA() { py::print("PyA.~PyA()"); }
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void f() override {
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py::print("PyA.f()");
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// This convolution just gives a `void`, but tests that PYBIND11_TYPE() works to protect
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// a type containing a ,
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PYBIND11_OVERLOAD(PYBIND11_TYPE(typename std::enable_if<true, void>::type), A, f);
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}
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};
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py::class_<A, PyA>(m, "A")
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.def(py::init<>())
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.def("f", &A::f);
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m.def("call_f", [](A *a) { a->f(); });
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// test_alias_delay_initialization2
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// ... unless we explicitly request it, as in this example:
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struct A2 {
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virtual ~A2() {}
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virtual void f() { py::print("A2.f()"); }
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};
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struct PyA2 : A2 {
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PyA2() { py::print("PyA2.PyA2()"); }
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~PyA2() { py::print("PyA2.~PyA2()"); }
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void f() override {
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py::print("PyA2.f()");
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PYBIND11_OVERLOAD(void, A2, f);
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}
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};
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py::class_<A2, PyA2>(m, "A2")
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.def(py::init_alias<>())
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.def(py::init([](int) { return new PyA2(); }))
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.def("f", &A2::f);
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m.def("call_f", [](A2 *a2) { a2->f(); });
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// test_dispatch_issue
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// #159: virtual function dispatch has problems with similar-named functions
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py::class_<Base, DispatchIssue>(m, "DispatchIssue")
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.def(py::init<>())
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.def("dispatch", &Base::dispatch);
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m.def("dispatch_issue_go", [](const Base * b) { return b->dispatch(); });
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// test_override_ref
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// #392/397: overriding reference-returning functions
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class OverrideTest {
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public:
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struct A { std::string value = "hi"; };
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std::string v;
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A a;
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explicit OverrideTest(const std::string &v) : v{v} {}
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virtual std::string str_value() { return v; }
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virtual std::string &str_ref() { return v; }
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virtual A A_value() { return a; }
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virtual A &A_ref() { return a; }
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virtual ~OverrideTest() = default;
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};
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class PyOverrideTest : public OverrideTest {
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public:
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using OverrideTest::OverrideTest;
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std::string str_value() override { PYBIND11_OVERLOAD(std::string, OverrideTest, str_value); }
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// Not allowed (uncommenting should hit a static_assert failure): we can't get a reference
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// to a python numeric value, since we only copy values in the numeric type caster:
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// std::string &str_ref() override { PYBIND11_OVERLOAD(std::string &, OverrideTest, str_ref); }
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// But we can work around it like this:
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private:
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std::string _tmp;
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std::string str_ref_helper() { PYBIND11_OVERLOAD(std::string, OverrideTest, str_ref); }
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public:
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std::string &str_ref() override { return _tmp = str_ref_helper(); }
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A A_value() override { PYBIND11_OVERLOAD(A, OverrideTest, A_value); }
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A &A_ref() override { PYBIND11_OVERLOAD(A &, OverrideTest, A_ref); }
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};
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py::class_<OverrideTest::A>(m, "OverrideTest_A")
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.def_readwrite("value", &OverrideTest::A::value);
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py::class_<OverrideTest, PyOverrideTest>(m, "OverrideTest")
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.def(py::init<const std::string &>())
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.def("str_value", &OverrideTest::str_value)
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// .def("str_ref", &OverrideTest::str_ref)
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.def("A_value", &OverrideTest::A_value)
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.def("A_ref", &OverrideTest::A_ref);
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}
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// Inheriting virtual methods. We do two versions here: the repeat-everything version and the
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// templated trampoline versions mentioned in docs/advanced.rst.
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//
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// These base classes are exactly the same, but we technically need distinct
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// classes for this example code because we need to be able to bind them
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// properly (pybind11, sensibly, doesn't allow us to bind the same C++ class to
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// multiple python classes).
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class A_Repeat {
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#define A_METHODS \
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public: \
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virtual int unlucky_number() = 0; \
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virtual std::string say_something(unsigned times) { \
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std::string s = ""; \
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for (unsigned i = 0; i < times; ++i) \
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s += "hi"; \
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return s; \
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} \
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std::string say_everything() { \
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return say_something(1) + " " + std::to_string(unlucky_number()); \
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}
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A_METHODS
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virtual ~A_Repeat() = default;
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};
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class B_Repeat : public A_Repeat {
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#define B_METHODS \
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public: \
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int unlucky_number() override { return 13; } \
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std::string say_something(unsigned times) override { \
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return "B says hi " + std::to_string(times) + " times"; \
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} \
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virtual double lucky_number() { return 7.0; }
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B_METHODS
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};
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class C_Repeat : public B_Repeat {
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#define C_METHODS \
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public: \
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int unlucky_number() override { return 4444; } \
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double lucky_number() override { return 888; }
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C_METHODS
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};
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class D_Repeat : public C_Repeat {
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#define D_METHODS // Nothing overridden.
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D_METHODS
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};
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// Base classes for templated inheritance trampolines. Identical to the repeat-everything version:
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class A_Tpl { A_METHODS; virtual ~A_Tpl() = default; };
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class B_Tpl : public A_Tpl { B_METHODS };
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class C_Tpl : public B_Tpl { C_METHODS };
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class D_Tpl : public C_Tpl { D_METHODS };
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// Inheritance approach 1: each trampoline gets every virtual method (11 in total)
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class PyA_Repeat : public A_Repeat {
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public:
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using A_Repeat::A_Repeat;
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int unlucky_number() override { PYBIND11_OVERLOAD_PURE(int, A_Repeat, unlucky_number, ); }
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std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, A_Repeat, say_something, times); }
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};
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class PyB_Repeat : public B_Repeat {
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public:
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using B_Repeat::B_Repeat;
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int unlucky_number() override { PYBIND11_OVERLOAD(int, B_Repeat, unlucky_number, ); }
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std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, B_Repeat, say_something, times); }
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double lucky_number() override { PYBIND11_OVERLOAD(double, B_Repeat, lucky_number, ); }
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};
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class PyC_Repeat : public C_Repeat {
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public:
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using C_Repeat::C_Repeat;
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int unlucky_number() override { PYBIND11_OVERLOAD(int, C_Repeat, unlucky_number, ); }
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std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, C_Repeat, say_something, times); }
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double lucky_number() override { PYBIND11_OVERLOAD(double, C_Repeat, lucky_number, ); }
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};
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class PyD_Repeat : public D_Repeat {
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public:
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using D_Repeat::D_Repeat;
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int unlucky_number() override { PYBIND11_OVERLOAD(int, D_Repeat, unlucky_number, ); }
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std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, D_Repeat, say_something, times); }
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double lucky_number() override { PYBIND11_OVERLOAD(double, D_Repeat, lucky_number, ); }
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};
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// Inheritance approach 2: templated trampoline classes.
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//
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// Advantages:
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// - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one for
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// any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes and 11
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// methods (repeat).
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// - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and can
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// properly inherit constructors.
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//
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// Disadvantage:
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// - the compiler must still generate and compile 14 different methods (more, even, than the 11
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// required for the repeat approach) instead of the 6 required for MI. (If there was no pure
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// method (or no pure method override), the number would drop down to the same 11 as the repeat
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// approach).
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template <class Base = A_Tpl>
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class PyA_Tpl : public Base {
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public:
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using Base::Base; // Inherit constructors
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int unlucky_number() override { PYBIND11_OVERLOAD_PURE(int, Base, unlucky_number, ); }
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std::string say_something(unsigned times) override { PYBIND11_OVERLOAD(std::string, Base, say_something, times); }
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};
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template <class Base = B_Tpl>
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class PyB_Tpl : public PyA_Tpl<Base> {
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public:
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using PyA_Tpl<Base>::PyA_Tpl; // Inherit constructors (via PyA_Tpl's inherited constructors)
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int unlucky_number() override { PYBIND11_OVERLOAD(int, Base, unlucky_number, ); }
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double lucky_number() override { PYBIND11_OVERLOAD(double, Base, lucky_number, ); }
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};
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// Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these (we can
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// use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead):
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/*
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template <class Base = C_Tpl> class PyC_Tpl : public PyB_Tpl<Base> {
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public:
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using PyB_Tpl<Base>::PyB_Tpl;
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};
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template <class Base = D_Tpl> class PyD_Tpl : public PyC_Tpl<Base> {
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public:
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using PyC_Tpl<Base>::PyC_Tpl;
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};
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*/
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void initialize_inherited_virtuals(py::module &m) {
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// test_inherited_virtuals
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// Method 1: repeat
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py::class_<A_Repeat, PyA_Repeat>(m, "A_Repeat")
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.def(py::init<>())
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.def("unlucky_number", &A_Repeat::unlucky_number)
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.def("say_something", &A_Repeat::say_something)
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.def("say_everything", &A_Repeat::say_everything);
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py::class_<B_Repeat, A_Repeat, PyB_Repeat>(m, "B_Repeat")
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.def(py::init<>())
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.def("lucky_number", &B_Repeat::lucky_number);
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py::class_<C_Repeat, B_Repeat, PyC_Repeat>(m, "C_Repeat")
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.def(py::init<>());
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|
py::class_<D_Repeat, C_Repeat, PyD_Repeat>(m, "D_Repeat")
|
|
.def(py::init<>());
|
|
|
|
// test_
|
|
// Method 2: Templated trampolines
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|
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<>());
|
|
|
|
|
|
// Fix issue #1454 (crash when acquiring/releasing GIL on another thread in Python 2.7)
|
|
m.def("test_gil", &test_gil);
|
|
m.def("test_gil_from_thread", &test_gil_from_thread);
|
|
};
|