1 /* Unit testing for outcomes 2 (C) 2013-2020 Niall Douglas <http://www.nedproductions.biz/> (14 commits) 3 4 5 Boost Software License - Version 1.0 - August 17th, 2003 6 7 Permission is hereby granted, free of charge, to any person or organization 8 obtaining a copy of the software and accompanying documentation covered by 9 this license (the "Software") to use, reproduce, display, distribute, 10 execute, and transmit the Software, and to prepare derivative works of the 11 Software, and to permit third-parties to whom the Software is furnished to 12 do so, all subject to the following: 13 14 The copyright notices in the Software and this entire statement, including 15 the above license grant, this restriction and the following disclaimer, 16 must be included in all copies of the Software, in whole or in part, and 17 all derivative works of the Software, unless such copies or derivative 18 works are solely in the form of machine-executable object code generated by 19 a source language processor. 20 21 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 22 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 23 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT 24 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE 25 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, 26 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 27 DEALINGS IN THE SOFTWARE. 28 */ 29 30 #define _CRT_SECURE_NO_WARNINGS 31 32 #include <boost/outcome/outcome.hpp> 33 #include <boost/test/unit_test.hpp> 34 #include <boost/test/unit_test_monitor.hpp> 35 36 #include <iostream> 37 38 namespace hook_test 39 { 40 using BOOST_OUTCOME_V2_NAMESPACE::in_place_type; 41 // Use static storage to convey extended error info from result construction to outcome conversion 42 static char extended_error_info[256]; 43 44 // Use the error_code type as the ADL bridge for the hooks by creating a type here 45 struct error_code : public boost::system::error_code 46 { 47 using boost::system::error_code::error_code; 48 error_code() = default; error_codehook_test::error_code49 error_code(boost::system::error_code ec) // NOLINT 50 : boost::system::error_code(ec) 51 { 52 } 53 }; 54 // Localise result to using the local error_code so this namespace gets looked up for the hooks 55 template <class R> using result = BOOST_OUTCOME_V2_NAMESPACE::result<R, error_code>; 56 // Specialise the result construction hook for our localised result hook_result_construction(result<int> * res,U &&)57 template <class U> constexpr inline void hook_result_construction(result<int> *res, U && /*unused*/) noexcept 58 { 59 // Write the value in the result into the static storage 60 snprintf(extended_error_info, sizeof(extended_error_info), "%d", res->assume_value()); // NOLINT 61 } hook_result_construction(result<std::string> * res,U &&)62 template <class U> constexpr inline void hook_result_construction(result<std::string> *res, U && /*unused*/) noexcept 63 { 64 // Write the value in the result into the static storage 65 snprintf(extended_error_info, sizeof(extended_error_info), "%s", res->assume_value().c_str()); // NOLINT 66 } 67 } // namespace hook_test 68 69 BOOST_OUTCOME_AUTO_TEST_CASE(works_result_hooks, "Tests that you can hook result's construction") 70 { 71 using namespace hook_test; 72 result<int> a(5); 73 BOOST_CHECK(!strcmp(extended_error_info, "5")); // NOLINT 74 result<std::string> b("niall"); 75 BOOST_CHECK(!strcmp(extended_error_info, "niall")); // NOLINT 76 } 77 78 //! [extended_error_coding2] 79 namespace hook_test 80 { 81 // Localise outcome to using the local error_code so this namespace gets looked up for the hooks 82 template <class R> using outcome = BOOST_OUTCOME_V2_NAMESPACE::outcome<R, error_code, std::string>; 83 84 // Specialise the outcome copy and move conversion hook for our localised result hook_outcome_copy_construction(outcome<T> * res,const result<U> &)85 template <class T, class U> constexpr inline void hook_outcome_copy_construction(outcome<T> *res, const result<U> & /*unused*/) noexcept 86 { 87 // when copy constructing from a result<T>, place extended_error_coding::extended_error_info into the payload 88 std::cout << "hook_outcome_copy_construction fires" << std::endl; 89 BOOST_OUTCOME_V2_NAMESPACE::hooks::override_outcome_exception(res, extended_error_info); 90 } hook_outcome_move_construction(outcome<T> * res,result<U> &&)91 template <class T, class U> constexpr inline void hook_outcome_move_construction(outcome<T> *res, result<U> && /*unused*/) noexcept 92 { 93 // when move constructing from a result<T>, place extended_error_coding::extended_error_info into the payload 94 std::cout << "hook_outcome_move_construction fires" << std::endl; 95 BOOST_OUTCOME_V2_NAMESPACE::hooks::override_outcome_exception(res, extended_error_info); 96 } 97 } // namespace hook_test 98 99 BOOST_OUTCOME_AUTO_TEST_CASE(works_outcome_hooks, "Tests that you can hook outcome's conversion from a result") 100 { 101 using namespace hook_test; 102 outcome<int> a(result<int>(5)); 103 BOOST_REQUIRE(a.has_exception()); // NOLINT 104 BOOST_CHECK(a.exception() == "5"); 105 outcome<std::string> b(result<std::string>("niall")); 106 BOOST_CHECK(b.exception() == "niall"); 107 108 // Make sure hook does not fire for any other kind of outcome copy or move, only when converting from our custom result only 109 outcome<int> c(5); 110 outcome<long> d(c); // can't be the same type as source, else copy elision takes place and no ADL hook calling 111 BOOST_CHECK(!d.has_exception()); 112 outcome<int> e(BOOST_OUTCOME_V2_NAMESPACE::result<int>(5)); 113 BOOST_CHECK(!e.has_exception()); 114 } 115