chrono_io.hpp: operator<<(ostream& os, ...) modifies the state of os

[vkh@…]

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.

[viboes]

I'm reworking the chrono io for version v2 which uses ios_base states instead of locale facets. Could you check if the version 2 solves the issue?

[viboes]

The issue is solved moving to version 2. You should define BOOST_CHRONO_VERSION=2.

Merged to release [80424][80430][80471].

[viboes]

I have no fix for io version 1. You should move to version 2.