peter.kourzanov@xxxxxxxxx wrote:
> On Wed, Apr 09, 2008 at 04:51:14PM +0100, Andrew Haley wrote:
>> Well, OK, you may either do
>>
>> int foo(int n, int p[])
>>
>> or
>>
>> int foo(int n, int p[])
>
> int bar(int n, int p[n]) I presume...
Yes.
> I am perfectly OK with sizeof returning sizeof(int*) for your
> foo() function, but it just feels so wrong to do it when the size
> is so easily accessible...
But it's *not* always easily accessible. In this case,
int bar(int p[n])
n is somewhere in global scope, maybe in another translation unit,
and as I point out below you'd have to copy it at the time the array
was created.
>> but sizeof doesn't distinguish these two cases. In any case, how would
>> you do it? Would an assignment to n change the result of sizeof, or not?
>> If not, you'd have to create a "shadow" variable.
>
>
> Sure not, it is not changed when you do (on a 32-bit platform):
>
> int foo()
> { int s=10,a[s];
> s=11;
> assert(sizeof s==40);
> }
>
> Try it... Why should the behaviour be so much different in the
> parameter passing case?
So, you're saying it *should* create a hidden copy of the size
parameter for use by sizeof? While this would work, it's not very
C.
Andrew.
