I have a mutable dynamic array of dchar, grown by successively appending more and more. When I wish to zap it and hand the contents to the GC to be cleaned up, what should I do? What happens if I set the .length to zero?

On Tuesday, 4 July 2023 at 17:01:42 UTC, Cecil Ward wrote:
> I have a mutable dynamic array of dchar, grown by successively appending more and more. When I wish to zap it and hand the contents to the GC to be cleaned up, what should I do? What happens if I set the .length to zero?

I do want to restart the .length at zero in any case as I’m going to begin the appending afresh, so I wish to restart from nothing.

On Tuesday, 4 July 2023 at 17:46:22 UTC, Steven Schveighoffer wrote:
> On 7/4/23 1:01 PM, Cecil Ward wrote:
>> I have a mutable dynamic array of dchar, grown by successively appending more and more. When I wish to zap it and hand the contents to the GC to be cleaned up, what should I do? What happens if I set the .length to zero?
>
> If you want to forget it so the GC can clean it up, set it to `null`. If you set the length to 0, the array reference is still pointing at it.
>
> If you want to reuse it (and are sure that no other things are referring to it), you can do:
>
> ```d
> arr.length = 0;
> arr.assumeSafeAppend;
> ```
>
> Now, appending to the array will reuse the already-allocated buffer space. Obviously, if you have data in there that is still used, you don't want to use this option.
>
> -Steve

Many many thanks for that tip, Steve!