Choosing an Approach for the Template Lowering of _d_arrayctor

[kinke]

On Friday, 26 November 2021 at 11:59:37 UTC, Stanislav Blinov 
wrote:
> On Friday, 26 November 2021 at 02:42:23 UTC, kinke wrote:
>> Note that this is exactly the current behavior of 
>> intimately-related .dup for non-POD slices: 
>> https://github.com/dlang/druntime/blob/595707b1ac8a439b2a7243b0abf95d4bc56239ff/src/object.d#L3601-L3627
>
> https://issues.dlang.org/show_bug.cgi?id=22547

Thanks for filing. What I wanted to get at is that there seems to 
be a need for a `copyEmplaceArray(S, T)(S[] source, T[] target)`, 
which can be used for _d_arrayctor, dup and copyEmplace (for 
static arrays). copyEmplace for static arrays currently handles 
throwing copies in yet another way 
(https://github.com/dlang/druntime/blob/595707b1ac8a439b2a7243b0abf95d4bc56239ff/src/core/lifetime.d#L1266-L1285), but that's already filed: https://issues.dlang.org/show_bug.cgi?id=22177

With copyEmplaceArray, _d_arrayctor could keep on 
stack-allocating the static array result and returning it via 
NRVO.