------- Comment #40 from paolo dot carlini at oracle dot com 2010-09-17 18:53 ------- In general, our users know that seeking allows to switch from reading to writing, and viceversa (when the stream has been appropriately opened of course). This assumption remained true for years and years. Thus, for now at least, I would rather not change it, whether the Standard is completely clear in this area or not.
Also, I don't think the name __is_tell is appropriate, because of course this kinf of situation in principle can occur also when tell is not involved (like in your testcase ;) Modulo the above comments, I think we can enable the optimization for codecvt too, yes, let me reformat your other tweaks and more cleanly incorporate the !(_M_mode & ios_base::out) thing. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45628