Array access via pointer

[Pelle]

On 05/30/2010 11:54 PM, Robert wrote:
> On 2010-05-30 23:12:06 +0200, "Simen kjaeraas" <simen.kjaras at gmail.com>
> said:
>
>> Going again with the C code:
>>
>> typedef struct array {
>> int* data;
>> int length;
>> };
>>
>> You would use an array like this:
>>
>> void foo( ) {
>> array arr;
>> arr.ptr = malloc(32);
>> arr.length = 8;
>> }
>>
>> Now, as you can probbly see, &arr would give the pointer to the
>> struct, not to the data. Basically, a pointer to pointer to int,
>> rather than the pointer to int you want.
>
> Ok, I thought that the structure was a bit more flat like:
>
> typedef struct array {
> int length;
> int[1..length] data;
> }
>
> Avoiding one indirection as it could be assumed that the
> memory-allocator / GC will return a continous piece for the array. But
> of course resizing and reallocation would be a bit more complicated.
>

Not avoiding an indirection if it's still located on the heap. I mean, 
pointer to (length and array), or (pointer and length) to array. Still 
just one level of indirection.

The fat pointer solution also allow for arbitrary slicing.