There seems to be change/regression in boost program options.

In boost/1.53. I used

   boost::program_options::variables_map vm;
   po::store( po::parse_command_line( argc, argv, desc_ ,
            po::command_line_style::unix_style ^ po::command_line_style::allow_short),
            vm );
   po::notify( vm );

This could handle arguments like:
./exe --help all
./exe --help summary

However from boost 1.59, this no longer works, instead I have to use:

./exe --help=all

./exe --help=summary

Is this a known change ? how do i get back to the old functionality ?

Ta,

Avi