[Boost-bugs] [Boost C++ Libraries] #6871: chrono_io.hpp: operator<<(ostream& os, ...) modifies the state of os

Subject: [Boost-bugs] [Boost C++ Libraries] #6871: chrono_io.hpp: operator<<(ostream& os, ...) modifies the state of os
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-05-06 15:09:32

#6871: chrono_io.hpp: operator<<(ostream& os, ...) modifies the state of os
-------------------------------------+--------------------------------------
 Reporter:  vkh@…                    |       Owner:  viboes 
     Type:  Bugs                     |      Status:  new    
Milestone:  To Be Determined         |   Component:  chrono 
  Version:  Boost Development Trunk  |    Severity:  Problem
 Keywords:                           |  
-------------------------------------+--------------------------------------
 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.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6871>
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