From: Tim Hunter <sastph@...>
Date: 2006-08-28T21:50:12+09:00
Subject: Re: Version Check in C Extension

elias.athanasopoulos@gmail.com wrote:
> Hello!
> 
> How can I check for the Ruby version inside a C extension? I found some
> constants in version.h, but I don't think that file is included via
> ruby.h and it has a very common name that may conflicts with similar
> files in other projects. So, I don't think it is wise to include
> version.h in a Ruby extension.
> 
> Is there another way to check if the extension gets compiled with Ruby
> 1.8 or 1.9?
> 
> Regards,
> Elias
> 

In your extconf.rb file construct a -D option from the RUBY_VERSION 
constant:

VERSION_NUMBER = '0x'+RUBY_VERSION.tr('.','')
$CPPFLAGS = "-DRUBY_VERSION=#{VERSION_NUMBER}"