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From: bart <bc@freeuk.com>
Newsgroups: comp.lang.c
Subject: =?UTF-8?Q?Re=3A_technology_discussion_=E2=86=92_does_the_world_need?=
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Date: Wed, 10 Jul 2024 15:49:11 +0100
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On 10/07/2024 14:32, Ben Bacarisse wrote:
> bart <bc@freeuk.com> writes:
> 
>> On 10/07/2024 00:35, Ben Bacarisse wrote:
>>> bart <bc@freeuk.com> writes:
>>>
>>>> On 09/07/2024 18:22, Ben Bacarisse wrote:
>>>>> bart <bc@freeuk.com> writes:
>>>>>
>>>>>> On 09/07/2024 16:58, Ben Bacarisse wrote:
>>>>>>> bart <bc@freeuk.com> writes:
>>>>>>>
>>>>>>>> Arrays are passed by reference:
>>>>>>>>
>>>>>>>>       void F(int a[20]) {}
>>>>>>>>
>>>>>>>>       int main(void) {
>>>>>>>>         int x[20];
>>>>>>>>         F(x);
>>>>>>>>       }
>>>>>>> This is the sort of thing that bad tutors say to students so that they
>>>>>>> never learn C properly.  All parameter passing in C is by value.  All of
>>>>>>> it.  You just have to know (a) what the syntax means and (b) what values
>>>>>>> get passed.
>>>>>>
>>>>>> The end result is that a parameter declared with value-array syntax is
>>>>>> passed using a reference rather than by value.
>>>>>>
>>>>>> And it does so because the language says, not because the ABI requires
>>>>>> it. A 2-byte array is also passed by reference.
>>>>> An address value is passed by value.  C has only one parameter passing
>>>>> mechanism.  You can spin it as much as you like, but C's parameter
>>>>> passing is simple to understand, provided learner tune out voices like
>>>>> yours.
>>>>
>>>> Little about C's type system is simple.
>>> Parameter passing is relatively simple though since there is only one
>>> mechanism -- pass by value.
>>
>> 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?!"

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.

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!