/* tests/test_custom-exceptions.cpp -- exception translation Copyright (c) 2016 Pim Schellart 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" // A type that should be raised as an exeption in Python class MyException : public std::exception { public: explicit MyException(const char * m) : message{m} {} virtual const char * what() const noexcept override {return message.c_str();} private: std::string message = ""; }; // A type that should be translated to a standard Python exception class MyException2 : public std::exception { public: explicit MyException2(const char * m) : message{m} {} virtual const char * what() const noexcept override {return message.c_str();} private: std::string message = ""; }; // A type that is not derived from std::exception (and is thus unknown) class MyException3 { public: explicit MyException3(const char * m) : message{m} {} virtual const char * what() const noexcept {return message.c_str();} private: std::string message = ""; }; // A type that should be translated to MyException // and delegated to its exception translator class MyException4 : public std::exception { public: explicit MyException4(const char * m) : message{m} {} virtual const char * what() const noexcept override {return message.c_str();} private: std::string message = ""; }; void throws1() { throw MyException("this error should go to a custom type"); } void throws2() { throw MyException2("this error should go to a standard Python exception"); } void throws3() { throw MyException3("this error cannot be translated"); } void throws4() { throw MyException4("this error is rethrown"); } void throws_logic_error() { throw std::logic_error("this error should fall through to the standard handler"); } void init_ex_custom_exceptions(py::module &m) { // make a new custom exception and use it as a translation target static py::exception ex(m, "MyException"); py::register_exception_translator([](std::exception_ptr p) { try { if (p) std::rethrow_exception(p); } catch (const MyException &e) { PyErr_SetString(ex.ptr(), e.what()); } }); // register new translator for MyException2 // no need to store anything here because this type will // never by visible from Python py::register_exception_translator([](std::exception_ptr p) { try { if (p) std::rethrow_exception(p); } catch (const MyException2 &e) { PyErr_SetString(PyExc_RuntimeError, e.what()); } }); // register new translator for MyException4 // which will catch it and delegate to the previously registered // translator for MyException by throwing a new exception py::register_exception_translator([](std::exception_ptr p) { try { if (p) std::rethrow_exception(p); } catch (const MyException4 &e) { throw MyException(e.what()); } }); m.def("throws1", &throws1); m.def("throws2", &throws2); m.def("throws3", &throws3); m.def("throws4", &throws4); m.def("throws_logic_error", &throws_logic_error); }