Function test_invoke_r

dlib/test/invoke.cpp:364–414

    };

    void test_invoke_r()
    {
        {
            static_assert(dlib::is_invocable_r<std::string, decltype(func_return_c_string)>::value, "should be invocable");
            auto str = dlib::invoke_r<std::string>(func_return_c_string);
            static_assert(std::is_same<decltype(str), std::string>::value, "bad return type");
            DLIB_TEST(str == "hello darkness my old friend");
        }

        {
            obj_return_c_string obj;
            static_assert(dlib::is_invocable_r<std::string, decltype(&obj_return_c_string::run), decltype(obj)>::value, "should be invocable");
            auto str = dlib::invoke_r<std::string>(&obj_return_c_string::run, obj);
            static_assert(std::is_same<decltype(str), std::string>::value, "bad return type");
            DLIB_TEST(str == "i've come to talk with you again");
        }

        {
            obj_return_c_string obj;
            static_assert(dlib::is_invocable_r<std::string, decltype(&obj_return_c_string::run), decltype(&obj)>::value, "should be invocable");
            auto str = dlib::invoke_r<std::string>(&obj_return_c_string::run, &obj);
            static_assert(std::is_same<decltype(str), std::string>::value, "bad return type");
            DLIB_TEST(str == "i've come to talk with you again");
        }

        {
            auto obj = std::make_shared<obj_return_c_string>();
            static_assert(dlib::is_invocable_r<std::string, decltype(&obj_return_c_string::run), decltype(obj)>::value, "should be invocable");
            auto str = dlib::invoke_r<std::string>(&obj_return_c_string::run, obj);
            static_assert(std::is_same<decltype(str), std::string>::value, "bad return type");
            DLIB_TEST(str == "i've come to talk with you again");
        }

        {
            std::unique_ptr<obj_return_c_string> obj(new obj_return_c_string());
            static_assert(dlib::is_invocable_r<std::string, decltype(&obj_return_c_string::run), decltype(obj)>::value, "should be invocable");
            auto str = dlib::invoke_r<std::string>(&obj_return_c_string::run, obj);
            static_assert(std::is_same<decltype(str), std::string>::value, "bad return type");
            DLIB_TEST(str == "i've come to talk with you again");
        }

        {
            auto lambda_return_c_string = [] {
                return "because a vision softly creeping";
            };
            static_assert(dlib::is_invocable_r<std::string, decltype(lambda_return_c_string)>::value, "should be invocable");
            auto str = dlib::invoke_r<std::string>(lambda_return_c_string);
            static_assert(std::is_same<decltype(str), std::string>::value, "bad return type");
            DLIB_TEST(str == "because a vision softly creeping");
        }
    }

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