• Cecil Ward (4/4) Jul 04 2023 I have a mutable dynamic array of dchar, grown by successively
• Cecil Ward (3/7) Jul 04 2023 I do want to restart the .length at zero in any case as I’m going
• Steven Schveighoffer (13/16) Jul 04 2023 If you want to forget it so the GC can clean it up, set it to `null`. If...
• Cecil Ward (3/21) Jul 04 2023 Many many thanks for that tip, Steve!

Cecil Ward <cecil cecilward.com> writes:

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?

Cecil Ward <cecil cecilward.com> writes:

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.

Steven Schveighoffer <schveiguy gmail.com> writes:

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

Cecil Ward <cecil cecilward.com> writes:

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!