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From: Janis Papanagnou <janis_papanagnou+ng@hotmail.com>
Newsgroups: comp.lang.c
Subject: =?UTF-8?Q?Re:_technology_discussion_=e2=86=92_does_the_world_need_a?=
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Date: Wed, 10 Jul 2024 17:09:56 +0200
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On 10.07.2024 16:49, bart wrote:
> On 10/07/2024 14:32, Ben Bacarisse wrote:
>>>
>>> Except when it comes to arrays.
>>
>> The oddity is that, in C, one can't pass arrays to functions at all.
>> That is one of the quirks that people learning C need to learn.  It does
>> not alter the fact that there is only parameter passing mechanism -- by
>> value.
>>
>> Your plan, of course, is to take that one place where C is relatively
>> simple
> 
> It is not that simple. It is confusing. It is error prone.
> 
> I earlier asked this:
> 
> "So if arrays aren't passed by value in C, and they aren't passed by
> reference, then how the hell ARE they passed?!"

Arrays are not passed to the function; the address if the first array
element is passed as a pointer value to the function.

> 
> I haven't had a reply yet. I still consider arrays in C to be 'passed'
> by a mechanism which is near-indistinguishable from actual
> pass-by-reference.

It can be distinguished. Call by reference means that you provide an
object to the function that can be changed in its environment. In C,
where a pointer to an array is passed, you can (for example) also
pass a 0-pointer value.

> 
> If somebody had proposed adding pass-by-reference for arrays, you'd say
> C doesn't need it, because whatever benefits it might have you, C
> already has!

This is obviously wrong. - You can (to some degree) emulate a reference
mechanism by using pointer values. But "C" doesn't have a mechanism to
pass "by reference". (Note that "pass by reference" is not a colloquial
term like we may colloquially use "reference". It's rather a technical
term with a specific - and I hope quite unique :-) - meaning.)

(For arrays it is (conveniently?) hidden by the language as designed,
but you can still observe it by behavioral side effects.)

There's also another advantage of references; try implementing such
simple things like binary tree operations (including updates) once
with references (in C++) and once with pointers emulating references.
(Or read some basic book about Algorithms and Data Structures where
you typically find such code and can simply study it.)

Janis