/* example/example2.cpp2 -- singleton design pattern, static functions and variables, passing and interacting with Python types Copyright (c) 2016 Wenzel Jakob All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. */ #include "example.h" #include #ifdef _WIN32 # include # include #endif class Example2 { public: static Example2 *new_instance() { return new Example2(); } ~Example2() { std::cout << "Destructing Example2" << std::endl; } /* Create and return a Python dictionary */ py::dict get_dict() { py::dict dict; dict[py::str("key")] = py::str("value"); return dict; } /* Create and return a Python set */ py::set get_set() { py::set set; set.add(py::str("key1")); set.add(py::str("key2")); return set; } /* Create and return a C++ dictionary */ std::map get_dict_2() { std::map result; result["key"] = "value"; return result; } /* Create and return a C++ set */ std::set get_set_2() { std::set result; result.insert("key1"); result.insert("key2"); return result; } /* Create, manipulate, and return a Python list */ py::list get_list() { py::list list; list.append(py::str("value")); cout << "Entry at positon 0: " << py::object(list[0]) << endl; list[0] = py::str("overwritten"); return list; } /* C++ STL data types are automatically casted */ std::vector get_list_2() { std::vector list; list.push_back(L"value"); return list; } /* C++ STL data types are automatically casted */ std::array get_array() { return std::array {{ "array entry 1" , "array entry 2"}}; } /* Easily iterate over a dictionary using a C++11 range-based for loop */ void print_dict(py::dict dict) { for (auto item : dict) std::cout << "key: " << item.first << ", value=" << item.second << std::endl; } /* Easily iterate over a set using a C++11 range-based for loop */ void print_set(py::set set) { for (auto item : set) std::cout << "key: " << item << std::endl; } /* Easily iterate over a list using a C++11 range-based for loop */ void print_list(py::list list) { int index = 0; for (auto item : list) std::cout << "list item " << index++ << ": " << item << std::endl; } /* STL data types (such as maps) are automatically casted from Python */ void print_dict_2(const std::map &dict) { for (auto item : dict) std::cout << "key: " << item.first << ", value=" << item.second << std::endl; } /* STL data types (such as sets) are automatically casted from Python */ void print_set_2(const std::set &set) { for (auto item : set) std::cout << "key: " << item << std::endl; } /* STL data types (such as vectors) are automatically casted from Python */ void print_list_2(std::vector &list) { #ifdef _WIN32 /* Can't easily mix cout and wcout on Windows */ _setmode(_fileno(stdout), _O_TEXT); #endif int index = 0; for (auto item : list) std::wcout << L"list item " << index++ << L": " << item << std::endl; } /* pybind automatically translates between C++11 and Python tuples */ std::pair pair_passthrough(std::pair input) { return std::make_pair(input.second, input.first); } /* pybind automatically translates between C++11 and Python tuples */ std::tuple tuple_passthrough(std::tuple input) { return std::make_tuple(std::get<2>(input), std::get<1>(input), std::get<0>(input)); } /* STL data types (such as arrays) are automatically casted from Python */ void print_array(std::array &array) { int index = 0; for (auto item : array) std::cout << "array item " << index++ << ": " << item << std::endl; } void throw_exception() { throw std::runtime_error("This exception was intentionally thrown."); } static int value; static const int value2; }; int Example2::value = 0; const int Example2::value2 = 5; void init_ex2(py::module &m) { /* No constructor is explicitly defined below. An exception is raised when trying to construct it directly from Python */ py::class_(m, "Example2", "Example 2 documentation") .def("get_dict", &Example2::get_dict, "Return a Python dictionary") .def("get_dict_2", &Example2::get_dict_2, "Return a C++ dictionary") .def("get_list", &Example2::get_list, "Return a Python list") .def("get_list_2", &Example2::get_list_2, "Return a C++ list") .def("get_set", &Example2::get_set, "Return a Python set") .def("get_set2", &Example2::get_set, "Return a C++ set") .def("get_array", &Example2::get_array, "Return a C++ array") .def("print_dict", &Example2::print_dict, "Print entries of a Python dictionary") .def("print_dict_2", &Example2::print_dict_2, "Print entries of a C++ dictionary") .def("print_set", &Example2::print_set, "Print entries of a Python set") .def("print_set_2", &Example2::print_set_2, "Print entries of a C++ set") .def("print_list", &Example2::print_list, "Print entries of a Python list") .def("print_list_2", &Example2::print_list_2, "Print entries of a C++ list") .def("print_array", &Example2::print_array, "Print entries of a C++ array") .def("pair_passthrough", &Example2::pair_passthrough, "Return a pair in reversed order") .def("tuple_passthrough", &Example2::tuple_passthrough, "Return a triple in reversed order") .def("throw_exception", &Example2::throw_exception, "Throw an exception") .def_static("new_instance", &Example2::new_instance, "Return an instance") .def_readwrite_static("value", &Example2::value, "Static value member") .def_readonly_static("value2", &Example2::value2, "Static value member (readonly)"); }