[Bug c++/58063] default arguments evaluated twice per call

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58063

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Ah, in case isn't obvious already: it only happens when the "I/O expression"
has the ! operator in front.