From: Timothy Hunter <TimHunter@...>
Date: 2006-08-28T09:37:00+09:00
Subject: Re: Defining a method with default arguments in C

Timothy Hunter wrote:
> Brian Takita wrote:
>> Hello,
>>
>> How can I define a default argument value such as the following in c?
>>
>> def foobar(arg=1)
>> end
>>
>> Thanks,
>> Brian Takita
>>
> Specify the number of arguments as -1 in rb_define_method:
>
> rb_define_method(myclass, "method_name", meth_fnc, -1);
>
> In your method use rb_scan_args to scan the argument list. If you 
> don't get enough arguments, use the default values instead.
>
My earlier post was incomplete. I should've explained that you should 
define your method like this:

VALUE meth_fnc(int argc, VALUE *argv, VALUE self)
{
    // stuff
}

argv is a C array of VALUEs, one for each argument passed to the method. 
argc is the number of VALUEs in argv.

rb_scan_args takes argc and argv as arguments.