标签：http io os sp on ef as c++ tt
http://www.cplusplus.com/reference/ios/ios/operator_not/
http://stackoverflow.com/questions/8117566/why-istream-object-can-be-used-as-a-bool-expression
http://stackoverflow.com/questions/22954106/istream-ostream-vs-bool
c++ istream(ostream)是如何转换为bool的
标签：http io os sp on ef as c++ tt
原文地址：http://www.cnblogs.com/qrlozte/p/4103699.html
