id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
5201	Negative numbers as options and values not parsed correctly	Mateusz Loskot	Vladimir Prus	"This issue has been reported initially on StackOverflow in question [http://stackoverflow.com/questions/4107087/accepting-negative-doubles-with-boostprogram-options Accepting negative doubles with boost::program_options] and later reminded on the mailing list in thread [http://lists.boost.org/Archives/boost/2011/02/176604.php program_options negative numbers]. Not sure if it is a bug or lack of feature, but seems it would be reasonable to have it solved.

Simply, program_options can not parse negative numbers as values of options. For example:

{{{
mycommand --extent -1.0 -2.0 -3.0 1.0 2.0 3.0 --some-other-argument somevalue
}}}

I discussed this issue with Volodya on IRC and there seems to be possible and not difficult to implement solution. Here is the chat script:

{{{
Nov 10 17:04:17 <mloskot>    volodya: I think it's feasible to refactor the loops in the cmdline parser to handle multitoken options with negative numbers as values. I have an idea to add ::multitoken(int exact_tokens_num) and make parser consuming as much values as the exact number of tokens specified, regardless how the options look like
Nov 10 17:04:26 <mloskot>    volodya: what you think about this idea?
Nov 10 17:04:28 <spitzi>    The question is - supposed that I want to make some quick-and-dirty struct for the sake of having related, named fields tied together, but without going through writing c'tors and operators. Can a list of such structs be initialized with boost::assign::list_of ?
Nov 10 17:05:30 <volodya>    mloskot: well, I think that if that translates into min and max number of tokesn of the option being equal to that value, it seems sane
Nov 10 17:05:53 <mloskot>    volodya: yes, basically that would be the thing
Nov 10 17:05:55 <volodya>    and of course, when min=max, there's no need to guessing.
Nov 10 17:05:59 <volodya>    ok, sounds good.
}}}
"	Bugs	new	To Be Determined	program_options	Boost Development Trunk	Problem			mail@…