id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
6871	chrono_io.hpp: operator<<(ostream& os, ...) modifies the state of os	vkh@…	viboes	"The code 
    std::locale loc = os.getloc();
    if (!std::has_facet<Facet>(loc))
        os.imbue(std::locale(loc, new Facet));
causes the state of os to be changed. It requires the CLIENT code to do own locale saving, like in
{
   boost::io::ios_locale_saver loc(std::cout);
   std::cout << boost::chrono::system_clock::now() << std::endl;
}

Compare this to stream io code in boost/date_time (e.g., gregorian_io.hpp), that begins with a (correct)
   boost::io::ios_flags_saver iflags(os);

Please fix chrono to behave similarly.

Discovered with 1.47.0 in chrono/chrono_io.hpp, but also exists on the trunk in chrono/io_v1/chrono_io.hpp."	Bugs	closed	Boost 1.52.0	chrono	Boost 1.47.0	Problem	wontfix