在try catch块中没有捕获异常

Question

我做了一个简单的抛出"TEST THROW"并没有捕到我的catch(std :: exception&e).是因为我正在捕捉一个std :: exception&e？我的意思是,只有从std :: exception派生的异常类才被捕获？如果没有,我做错了什么还是正常的？顺便说一下,两个catch块都没有捕获抛出异常.

int main()
{
try
{
    throw "TEST THROW"; // TEST
    Core core;

    core.Init();
    core.Load();

    while (!core.requestCloseWindow)
    {
        core.HandleInput();

        core.Update();
        core.Draw();
    }

    core.Unload();
    core.window->close();
}
catch (std::exception& e)
{
    std::cerr << e.what() << std::endl;
    try
    {
        time_t rawTime;
        struct tm* timeInfo;
        char timeBuffer [80];

        time(&rawTime);
        timeInfo = localtime(&rawTime);

        strftime(timeBuffer, 80, "%F %T", timeInfo);
        puts(timeBuffer);

        std::ofstream ofs; // Pas besoin de close, car le destructeur le fait.
        ofs.exceptions(std::ofstream::failbit | std::ofstream::badbit);
        ofs.open("log.txt", std::ofstream::out | std::ofstream::app);
        ofs << e.what() << std::endl;
    }
    catch (std::exception& e)
    {
        std::cerr << "An error occured while writing to a log file!" << std::endl;
    }
}

return 0;

}

Answer 1

你扔了一个const char*.std::exception只捕获它std::exception和它的所有派生类.所以为了抓住你的投掷,你应该投掷std::runtime_error("TEST THROW").或者std::logic_error("TEST THROW"); 无论什么更合适.的派生类std::exception在这里列出.

Answer 2

人们可能会遇到这个问题的另一个原因,特别是如果他们最近一直在编写Java,他们可能会抛出指向异常的指针.

/* WARNING WARNING THIS CODE IS WRONG DO NOT COPY */
try {
    throw new std::runtime_error("catch me");
} catch (std::runtime_error &err) {
    std::cerr << "exception caught and ignored: " << err.what() << std::end;
}
/* WARNING WARNING THIS CODE IS WRONG DO NOT COPY */

会不会赶std::runtime_error*你扔.它可能会std::terminate因为未被捕获的异常的召唤而死亡.

不要分配异常new,只需抛出构造函数的值,例如

try {
    /* note: no 'new' here */
    throw std::runtime_error("catch me");
} catch (std::runtime_error &err) {
    std::cerr << "exception caught and ignored: " << err.what() << std::end;
}