问题描述
我在这里看到了一个有用的开始:
I saw a useful start here:
http://www.cs.technion.ac.il/~imaman/programs/teestream.html
制作一个新的流，它可以同时进入堵塞和日志文件.
And it works great to make a new stream which goes to both clog and a log file.
但是，如果我尝试将 clog 重新定义为新流，它将不起作用，因为新流与 clog 具有相同的 rdbuf()，因此以下内容无效:
However, if I try to redefine clog to be the new stream it does not work because the new stream has the same rdbuf() as clog so the following has no effect:
clog.rdbuf(myTee.rdbuf());
那么如何修改 tee 类以拥有自己的 rdbuf()，然后它可以成为 clog 的目标?
So how can I modify the tee class to have its own rdbuf() which can then be the target of clog?
谢谢.
-威廉
推荐答案
如果你真的想继续为 tee 使用 std::clog 而不是将输出发送到不同的流，你需要工作低一级:而不是源自ostream，源自streambuf.然后你可以这样做:
If you really want to keep using std::clog for the tee instead of sending output to a different stream, you need to work one level lower: Instead of deriving from ostream, derive from streambuf. Then you can do this:
fstream logFile(...);
TeeBuf tbuf(logFile.rdbuf(), clog.rdbuf());
clog.rdbuf(&tbuf);
有关如何派生自己的 streambuf 类的更多信息，请参阅 此处.
For more information on how to derive your own streambuf class, see here.
这篇关于如何将木屐重新定义为原始木屐和日志文件?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！