[boost] Re: program_options bool_switch usage string

From: Jonathan Graehl (jonathan_at_[hidden])
Date: 2004-09-16 13:43:17

>
>
>here's another possibility:
>
>   value<type>(&variable, "filename")->......
>
>something like that was in the pre-review version, with the difference that
>the value name was also used to specify flags, e.g "filename?" would mean
>the value is optional.
>
>  
>

Yes ... I like this best.

>> Also, I'm not sure why 0-argument items couldn't appear in a config
>> file.  I declare the number of arguments used by options before I parse
>> the config file, after all.
>
>Because the current config parser, systantically, requires that everything
>specified there has a value. If you specify that an option accepts no
>explicit value, it can't be present in config file.
>

OK, your statement was with reference to the current config parser ;)

A newer parser could recognize the end of an option name first, then 
interrogate the option to see if it takes an argument, then if it does, 
expect to parse a "= value".