Replace druntime Hooks with Templates: Milestone 1, Week 2

[Johan]

On Monday, 3 October 2022 at 20:28:19 UTC, Teodor Dutu wrote:
> Hi,
>
> This week I faced a few setbacks with `_d_arraycatnTX` due to 
> type mismatches.
> Due to the hustle of moving house, I haven't made much progress 
> on this front.
>
> To take a break from this, I temporarily moved on to the 
> `_d_newitem{T,iT,U}` hooks.
> I implemented templated one templated hook for `_d_newitemT` 
> and added unittests for it.
> The difference will now be made by the compiler during the 
> lowering, by calling the constructor, copying the default 
> initialiser, or doing nothing (`void` initialisation).

Hi Teodor,
   Are you aware about the capability to override these 
implementations by the user? DMD itself is using this, see for 
example: 
https://github.com/dlang/dmd/blob/16fad687b0e894879564864d7eb75747fb41a057/compiler/src/dmd/root/rmem.d#L257-L262

Is this still possible after your work?

regards,
   Johan