Re: technology discussion → does the world need a "new" C ?

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Sujet : Re: technology discussion → does the world need a "new" C ?
De : bc (at) *nospam* freeuk.com (bart)
Groupes : comp.lang.c
Date : 09. Jul 2024, 17:29:57
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <v6joi4$1epoj$1@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
User-Agent : Mozilla Thunderbird
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.

 void F(int a[20]) ... declares a to be of type int *.  Feel free to rail
about that as much as you like but that is what that syntax means.
 The x in F(x) is converted to a pointer to x[0] since the x is not an
operand of &, sizeof etc.  F(x) passes a pointer by value.  F receives a
pointer value in a.
 
Although the type of 'a' inside 'F' will be int* rather than
int(*)[20].
 No.  a is of type int *.
And that is different 'int*' how, about from having an extra space which C says is not signigicant in this context?

Date Sujet#  Auteur
5 Jul 24 * Re: technology discussion → does the world need a "new" C ?306Lawrence D'Oliveiro
5 Jul 24 `* Re: technology discussion → does the world need a "new" C ?305BGB
5 Jul 24  +* Re: technology discussion → does the world need a "new" C ?2Lawrence D'Oliveiro
5 Jul 24  i`- Re: technology discussion → does the world need a "new" C ?1yeti
5 Jul 24  +* Re: technology discussion → does the world need a "new" C ?275Keith Thompson
5 Jul 24  i+- Re: technology discussion → does the world need a "new" C ?1Lawrence D'Oliveiro
15 Jul 25  i`- 
5 Jul 24  +* Re: technology discussion → does the world need a "new" C ?26bart
5 Jul 24  i+- Re: technology discussion → does the world need a "new" C ?1BGB
6 Jul 24  i`* Re: technology discussion → does the world need a "new" C ?24Lawrence D'Oliveiro
6 Jul 24  i +* Re: technology discussion → does the world need a "new" C ?17Keith Thompson
6 Jul 24  i i+- Re: technology discussion → does the world need a "new" C ?1Janis Papanagnou
6 Jul 24  i i`* Re: technology discussion → does the world need a "new" C ?15Lawrence D'Oliveiro
6 Jul 24  i i +- Re: technology discussion → does the world need a "new" C ?1Ben Bacarisse
6 Jul 24  i i +- Re: technology discussion → does the world need a "new" C ?1Keith Thompson
7 Jul 24  i i +* Re: technology discussion → does the world need a "new" C ?10James Kuyper
10 Jul 24  i i i`* Re: technology discussion → does the world need a "new" C ?9Lawrence D'Oliveiro
10 Jul 24  i i i `* Re: technology discussion → does the world need a "new" C ?8James Kuyper
11 Jul 24  i i i  `* Re: technology discussion → does the world need a "new" C ?7Lawrence D'Oliveiro
11 Jul 24  i i i   +* Re: technology discussion → does the world need a "new" C ?2David Brown
11 Jul 24  i i i   i`- Re: technology discussion → does the world need a "new" C ?1Malcolm McLean
11 Jul 24  i i i   +* Re: technology discussion → does the world need a "new" C ?3bart
11 Jul 24  i i i   i`* Re: technology discussion → does the world need a "new" C ?2Chris M. Thomasson
12 Jul 24  i i i   i `- Re: technology discussion → does the world need a "new" C ?1Chris M. Thomasson
11 Jul 24  i i i   `- Re: technology discussion → does the world need a "new" C ?1James Kuyper
7 Jul 24  i i +- Re: technology discussion → does the world need a "new" C ?1Tim Rentsch
25 Aug 24  i i `- Re: technology discussion ? does the world need a "new" C ?1dave thompson 2
6 Jul 24  i +- Re: technology discussion → does the world need a "new" C ?1Janis Papanagnou
6 Jul 24  i +- Re: technology discussion → does the world need a "new" C ?1James Kuyper
6 Jul 24  i `* Re: technology discussion → does the world need a "new" C ?4bart
7 Jul 24  i  `* Re: technology discussion → does the world need a "new" C ?3Keith Thompson
7 Jul 24  i   `* Re: technology discussion → does the world need a "new" C ?2bart
7 Jul 24  i    `- Re: technology discussion → does the world need a "new" C ?1Keith Thompson
5 Jul 24  `- Re: technology discussion → does the world need a "new" C ?1lexi hale

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