`ios_base' undeclared 错误及解决

 本来可编译的代码，换了个低版本的RedHat就报错： “`ios_base' undeclared (first use this function)”

估计是低版本的g++所配的libstdc++有问题，但不知如何简单的解决。

还好一搜就查到一个帖子： http://mailman.powerdns.com/pipermail/pdns-users/2003-October/000771.html

Hmm, ios_base is defined in the C++ standard, but it isn't supported by g++
2.95.x. You can replace "ios_base" with "ios" to make it compile with g++
2.95.x (that's what I have done to make it compile on Debian woody).

照样改一下就好了。