range based for loops

[paulpach]

I figured that rather than add to my post in quora, I could just add items as issues as I find them.
Feel free to delete the issue if you want me to stop.

Consider using range based for loops, for example, instead of this:

    for (int i = 0; i < thread_num; i++) {
        threads[i]->_join();
    }

you could do:

    for (auto thread: threads) {
        thread->join();
    }

They are part of C++ 11 and make the code a lot more readable. In some cases it can make the code faster, for example if you are using a linked list.