snprintf is a better tool for this task, anyway, but here's what was
wrong with the stream formatting:
s << name << ":" << std::setw(45 - (int)s.tellp())
cannot be used to align columns, tellp() may return any of:
0
name.length()
name.length() + strlen(":")
because the compiler is allowed to reorder the evaluation of
sub-expressions as it likes -- it may evaluate s.tellp() before
evaluating (s << name) or in-between (s << name) and (s << ":")
try with gcc-4.8
90fcdc90d3