From: "Brian F. Feldman" <green@...>
Date: 2001-09-24T04:15:28+09:00
Subject: [ruby-talk:21609] Re: Please translate this easy snip of C++ to Ruby

Phlip <phlip_cpp@my-deja.com> wrote:
> Ruby Users:
> 
> Ogle this awesome snip of C++:
> 
>         #define TRACE_(x) cout << #x ": " << x << endl
> 
> When you use that like this:
> 
>         TRACE_(y + z);
>         TRACE_(strAnimals);
>         TRACE_(__LINE__);
> 
> the program emits this:
> 
>         y + z: 12
>         strAnimals: Lemmings
>         __LINE__:  69
> 
> Mighty healthy and easy to write debug statements with, huh? Saves a lot of 
> keystrokes, huh?
> 
> How do I do that, just as easy to call (meaning without extra "" quotes or 
> anything), in Ruby?

You don't.  Ruby Is Not C.  It doesn't use a magic preprocessor.  If you 
want something not be evaluated, you have a funny way of expressing it by 
writing them as plain variables and expecting some kind of magic to not 
evaluate them.  There are a couple magic things like that already, and there 
shouldn't be any more.

What is hard about puts("foo(blah): #{foo(blah)}")?  C++ definitely doesn't 
have the ability to do something like evaluating code embedded in strings, 
does it?

-- 
 Brian Fundakowski Feldman           \  FreeBSD: The Power to Serve!  /
 green@FreeBSD.org                    `------------------------------'