[Boost-bugs] [Boost C++ Libraries] #9545: program_options description printout bug

Subject: [Boost-bugs] [Boost C++ Libraries] #9545: program_options description printout bug
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-01-06 12:29:02

#9545: program_options description printout bug
------------------------------------------+-----------------------------
 Reporter:  Torquil Sørensen <torquil@…>  |      Owner:  vladimir_prus
     Type:  Bugs                          |     Status:  new
Milestone:  To Be Determined              |  Component:  program_options
  Version:  Boost 1.55.0                  |   Severity:  Problem
 Keywords:                                |
------------------------------------------+-----------------------------
 When setting the default value of a float option to 0.05, the help
 description that is printed by the program states that the default value
 is 0.0500000007. For double, it states "0.050000000000000003". The value
 of the variable within the program is correct, i.e. 0.05.

 I'm compiling with:

 $ g++ --version
 g++ (GCC) 4.8.3 20131226 (prerelease)

 Here is a test program that reproduces the problem when run with the
 option "--help":

 {{{
 #include "boost/program_options.hpp"

 int main(int argc, char ** argv)
 {
         float dt;

         boost::program_options::variables_map vm;
         boost::program_options::options_description desc("Description");
         desc.add_options()
                 ("help", "Print help message")
                 ("dt",
 boost::program_options::value<float>(&dt)->default_value(0.05), "Time
 step")
         ;

 boost::program_options::store(boost::program_options::parse_command_line(argc,
 argv, desc), vm);
         boost::program_options::notify(vm);

         if(vm.count("help")) desc.print(std::cout);

         std::cout << "dt = " << dt << "\n";

         return 0;
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9545>
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