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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: technology discussion =?utf-8?Q?=E2=86=92?= does the world need
 a "new" C ?
Date: Sat, 17 Aug 2024 07:41:01 -0700
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Bart <bc@freeuk.com> writes:

> On 16/08/2024 01:08, Ben Bacarisse wrote:
>
>> Bart <bc@freeuk.com> writes:
>>
>>> On 15/08/2024 15:33, Ben Bacarisse wrote:
>>>
>>>> Bart <bc@freeuk.com> writes:
>>>>
>>>>> On 15/08/2024 09:43, Tim Rentsch wrote:
>>>>>
>>>>>> Bart <bc@freeuk.com> writes:
>>>>>>
>>>>>>                            C call-by-value         call-by-reference
>>>>>>                            ===============         =================
>>>>>>      at call:
>>>>>>
>>>>>>        (array argument)    F(A)                    H(A)
>>>>>>
>>>>>>        (pointer argument)  F(p)                    (disallowed)
>>>>>
>>>>> My posts were about passing *arrays* and the fact that C's pass-by-value
>>>>> was remarkably similar to pass-by-reference.
>>>>
>>>> Which is why, presumably, you didn't show the differences.  Your
>>>> post was all polemic not part of a collegiate discussion of the
>>>> similarities and differences.
>>>>
>>>>> However your entry for pointers is not correct:
>>>>
>>>> No, the entry is correct.  H(p) would be (is?) disallowed when H's
>>>> parameter is a reference to an array.
>>>
>>> Sorry, what language does the right-hand column pertain to? /Any/ language
>>> that has call-by-reference, or Tim's hypthetical language?
>>
>> Tim said that case was "disallowed".  You call that an error on his
>> part.  What language did you have in mind that permits such a gross
>> warping of types?  I would describe /any/ language that allowed it as
>> having a design error.
>
> You or he would have to go into more detail, such as an actual
> example, to demonstrate whatever it is that you think is wrong about
> passing a pointer argument by-reference.
>
> I assume here that the language in the right column is not C.
>
>>> Or any that could be used to prove him right?
>>>
>>> In general there is no reason, in a language with true call-by-reference,
>>> why any parameter type T (which has the form U*, a pointer to anything),
>>> cannot be passed by reference.  It doesn't matter whether U is an array
>>> type or not.
>>
>> I can't unravel this.  Take, as a concrete example, C++.  You can't pass
>> a pointer to function that takes an array passed by reference.  You can,
>> of course, pass a pointer by reference, but that is neither here nor
>> there.
>
> OK.  So why do you agree with this:
>
>>>>>>                            C call-by-value         call-by-reference
>>>>>>                            ===============         =================
>>>>>>        (pointer argument)  F(p)                    (disallowed)
>
> What is 'pointer argument' here?

Try thinking harder.  Everyone else understood.