id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
9545,program_options description printout bug,Torquil Sørensen <torquil@…>,Vladimir Prus,"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;
}
}}}

",Bugs,new,To Be Determined,program_options,Boost 1.55.0,Problem,,,torquil@…