If T[new] is the container for T[], then what is the container for T[U]?

[Robert Jacques]

On Sat, 25 Apr 2009 19:44:18 -0400, Andrei Alexandrescu  
<SeeWebsiteForEmail at erdani.org> wrote:
> Christopher Wright wrote:
>> Simple solution: put the array definition in object.d and try  
>> implementing arrays with reference counting or manual memory management.
>>  I think stored slices break manual memory management, even with a  
>> dedicated slice type; but they should work just fine with refcounting.  
>> If you don't want to change the language, object.Array will have to  
>> implement the logic for slices and for allocated arrays. It's a bit  
>> ugly, and it makes the Array type larger. Also, Array's reference count  
>> would need to be accessed by reference.
>
> There are three schemes that are good starting points:
>
> 1. As right now :o).
>
> 2. Using refcounting. Arrays will be 4 words long (begin, end,  
> end-of-store, refcount*) and slices will be 3 words long (begin, end,  
> and owner*)

Or, use (begin, length, store*) for both arrays and slices and have the  
store contain (start, capacity, refcount).

> 3. Using manual management. Arrays will be 3 words long (begin, end,  
> end-of-store) and slices will be 2 words long (begin, end). This is  
> close to C++/STL. This case is less safe but very efficient.

Why store end-of-store? It's trivial to compute from the length. (If you  
have separate slice and array types, that is)

> If we manage to integrate them all... that's quite the holy grail. And I  
> think it's entirely possible with only a few changes to the language.
>
>
> Andrei