From: Xavier Noria <fxn@...>
Date: 2007-01-28T03:52:23+09:00
Subject: Re: pass by reference?

On Jan 27, 2007, at 7:29 PM, Austin Ziegler wrote:

> On 1/26/07, Vincent Fourmond <vincent.fourmond@9online.fr> wrote:
>> Andy Koch wrote:
>> > Hello,
>> >
>> > Is there a way to pass variables by reference into function.
>> >
>> > I have large string to pass and the pass by value seems to be  
>> eating up
>> > too much memory.
>>
>>   You don't actually need to do anything: everything in ruby is  
>> passed
>> by reference, (excepted integers, symbols, nil, false and true - am I
>> missing one ?)
>
> Those are still passed by reference. It just so happens that they are
> unique and immutable in the system, so it looks a lot like
> pass-by-value.

I think the problem in these discussions is that "reference" in the  
programming language jargon is not the same word as in "pass-by- 
reference". This discussion is common in Java forums as well. Java is  
pass-by-value.

In C++ since the copy constructor is involved, I found people in  
freenode#c++ consider &-arguments to be pass-by-reference because  
they can modify the objects in the caller, albeit the assigment test  
discussed in the thread does not work, that'd be

   def m(b)
     b = 7
   end

   a = 3
   m(a)
   # a expected to be 7 in pass-by-reference

-- fxn