一个好用的C++日志产生类，不但好用，而且它也很老，好像是老外写的，虽然这么多年了，但还是有很多人在用这个日志类。-A nice log generated C++ classes, is not only easy to use, and it is also very old, seems to be written by foreigners, although so many years, but there are still many people use this log clas