Re: Genuine copy of an element from an associative array

[Holzofen via Digitalmars-d-learn]

On Sunday, 6 October 2024 at 10:53:28 UTC, Nick Treleaven wrote:

On Thursday, 3 October 2024 at 12:23:27 UTC, Holzofen wrote:

[...]

Could anybody point me to a way how to make a straight copy without meddling with the source array?

You can copy an AA using `dup`:
https://dlang.org/phobos/object.html#.dup

Unfortunately this doesn't work:

    uint64[uint64] backup = factorials[n].dup;

https://issues.dlang.org/show_bug.cgi?id=11725

Instead you can use:

    auto backup = cast(uint64[uint64]) factorials[n].dup;

I think casting away const is OK because the AA produced by `dup` is unique, and the element type doesn't have indirections.

Thanks a lot!