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From: bart <bc@freeuk.com>
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Subject: =?UTF-8?Q?Re=3A_technology_discussion_=E2=86=92_does_the_world_need?=
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Date: Wed, 10 Jul 2024 17:48:57 +0100
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On 10/07/2024 16:54, James Kuyper wrote:
> On 10.07.2024 16:49, bart wrote:
> ...
>> "So if arrays aren't passed by value in C, and they aren't passed by
>> reference, then how the hell ARE they passed?!"
> 
> The problem with that question is the same as the problem with the
> question "How are Justices of the US Supreme Court elected?". They
> aren't elected, so the question cannot be answered. Arrays cannot be
> passed in C, so the question of how they are passed also cannot be answered.
> 
> You can pass a pointer to the start of an array or a pointer to the
> whole array; either way,

How is that interestingly different from pass-by-reference?

Which as you know involves a pointer to the value of an object, so the 
values are not passed, only the value of the pointer.

(You may also know that every language will use pass-by-value for 
everything if you delve deeply enough.)

In C, if you have this char[4] array at this address:

   01003F8  65 66 67 00

and try to pass it to a function defined with a char[4] argument, it 
will end up passing the address 01003F8.

If I pass the same array in a similar language but using explicit 
pass-by-reference, it will also pass the address 01003F8.

So, if you were to examine the machine code of such a program which was 
generated from one of those two languages, could you tell whether it was 
from the one with true pass-by-reference, or from C which only has 
pass-by-value?