From: Elias Athanasopoulos <elathan@...>
Date: 2004-03-30T01:32:31+09:00
Subject: Re: Obtaining size of Ruby objects in C

On Thu, Mar 25, 2004 at 08:54:34PM +0900, Christopher C.Aycock wrote:
> I'm writing a wrapper over a C function for Ruby. Because the Ruby 
> function has dynamic features that the C version does not, I can't use 
> SWIG and have to write everything by hand. I was wondering if anyone 
> knows how to obtain the size (in bytes) of a single element of an array.

I can't understand why SWIG fails.

> For example, if I have an array of type T, then sizeof (T) would give 
> me what I'm looking for. The C wrapper is being passed a VALUE type 
> parameter that should represent an array from the user. Is there a way 
> to determine the type of the array, plus the number of bytes of that 
> type?

You have to check its of the array's elements if you want to find the 
overall memory stamp of the array, but still I can't figure out why
you want to do such a thing.

Also, there isn't *a type* of a Ruby array. This is true, in a sense,
only for homogeneous arrays, but Ruby arrays are not, in general, 
homogeneous (i.e. different types can co-exist in a single array).

Regards,
-- 
University of Athens			I bet the human brain 
Physics Department				is a kludge --Marvin Minsky