You're correct that the problems you're having come from the destruction of of
. Wouldn't something like this (untested) work?
std::shared_ptr<std::ostream>
out_stream(const std::string &fname) {
if (fname.length() > 0)
std::shared_ptr<std::ostream> p(new std::ofstream(fname));
else
std::shared_ptr<std::ostream> p(new std::ostream(std::cout.rdbuf()));
}