From: DaZoner <bugmenot@...>
Date: 2004-12-16T01:17:25+09:00
Subject: Re: 64-bit integers in Ruby/DL


I don't know very much about Ruby/DL but can't you just define a struct that 
has two 32-bit numbers in it, and manipulate and pass those?

"Jamis Buck" <jamis_buck@byu.edu> wrote in message 
news:20041214220549.GA15605@serling.WorkGroup...
> Okay, you C gurus out there. Here's a stumper.
>
> Is there any way, without modifying Ruby/DL itself, to specify
> a function that returns a 64-bit integer using Ruby/DL? And to pass
> a 64-bit integer to a function?
>
> Consider:
>
>  require 'dl/import'
>  module Test64
>    dlload "foo.so"
>    extern "long long int get_64bit_value()"
>    extern "void set_64bit_value(long long int)"
>  end
>
> The above results in an error, currently, because Ruby/DL does not
> support 64-bit integers as immediate values.
>
> I thought of using a double (which is 64 bits, on my platform anyway):
>
>  require 'dl/import'
>  module Test64
>    dlload "foo.so"
>    extern "double get_64bit_value()"
>    extern "void set_64bit_value(double)"
>  end
>
>  result = Test64.get_64bit_value
>  p [result].pack("D").unpack("LL")
>
> But the value that comes back is nothing like what the function itself
> is really returning...
>
> Any clever tricks I can try? Anyone? Please?
>
> - Jamis
>
> -- 
> Jamis Buck
> jgb3@email.byu.edu
> http://www.jamisbuck.org/jamis
>
>
>