Pointer semantics in CTFE

[Patrik Strand]

On Tuesday, 29 May 2012 at 17:35:12 UTC, Michel Fortin wrote:
> On 2012-05-29 15:09:00 +0000, Artur Skawina 
> <art.08.09 at gmail.com> said:
>
>>   int a[1024];
>>   int[] da = a[0..1024];
>> 
>>   if (whatever)
>>      da = da[3..14];
>>   if (something_else)
>>      da = [42] ~ da;
>>   // etc
>> 
>>   if (da_is_a_slice_of_a())
>>      still_inside_a();
>> 
>> How do you implement da_is_a_slice_of_a()?
>
> Indeed, for that to work you'd still need to handle this case 
> specially. My bad for not catching that.
>
> Personally, I think it'd be much cleaner to go with some kind 
> of magic function than trying to match the condition against a 
> predefined pattern. Something like da.isSliceOf(a), which could 
> do the usual pointer thing at runtime and call some sort of 
> CTFE intrinsic at compile-time.

it would be elegant to reuse 'in', but is it too error-prone?

int[10] tmp;
int*    ptr = &tmp[4];

if(ptr in tmp) // O(1), i.e. ok.
{
}