From: Mike <michaelst@...>
Date: 2007-03-12T09:50:13+09:00
Subject: Re: #define alternative for Ruby

On Mar 12, 1:52 am, Daniel Berger <djber...@gmail.com> wrote:
> Michael Strelnikov wrote:
> > Hello all,
>
> >   Does Ruby have something like "#define" for C/C++? Especially with
> > arguments like "#define foo(x) (something_done_with_x(x))".
>
> >   Please don't say that "def" do the same. It doesn't.
>
> The closest analogue is to conditionally define a constant, then used
> defined? on that constant.
>
> For example, I do something like this in the windows-pr project, where
> some methods are not supported by Win2k or earlier:
>
> module Windows
>    module Console
>      begin
>        AttachConsole = Win32API.new('kernel32','AttachConsole','L', 'I')
>      rescue LoadError
>        # Requires Windows XP or later
>      end
>    end
> end
>
> And then, while using the above module:
>
> class MyConsoleClass
>     include Windows::Console
>
>     def test
>        if defined? AttachConsole
>           # do something
>        else
>           # do something else
>        end
>     end
> end
>
> Regards,
>
> Dan

I was talking more about macros rather then constants.
But I agree that constant are convenient way to substitute "#define
myconst 15". But can you substitute "#define myfunc(x)
(sin(x)*cos(x)*exp(x))"?
You should know that "x" could be as much other functions as a
constant/variable.