Re: pointers, assignments, Garbage Collection Oh My?

[Maxim Fomin]

On Thursday, 11 July 2013 at 17:07:18 UTC, Ali Çehreli wrote:
On 07/11/2013 12:23 AM, Jacob Carlborg wrote:
> On 2013-07-10 20:22, Ali Çehreli wrote:
>
>> And to be pedantic, length comes first:
>>
>> struct Array (T)
>> {
>>      size_t length;
>>      T* ptr;
>> }
>
> I thought "ptr" came first, that's the reason you could cast
to the
> pointer type. Not that one should do that. Perhaps there's
some
> compiler/runtime magic involved.

There must be little magic and that magic should be the same as 
getting the .ptr property. Otherwise, the "value" of a struct 
object cannot be casted to pointer type:

struct S
{
    int *p;
}

    auto s = S();
    int *p = cast(int*)s;

Error: e2ir: cannot cast s of type S to type int*

Ali

In context of slices cast(int*)arr is essentially s.ptr. There is 
no magic but accessing right field of struct.