Predefined Versions for Apple Operating Systems

[Michael K. Huntington]

On Saturday, 21 June 2025 at 20:24:34 UTC, Walter Bright wrote:
> Currently, the following predefined versions exist for Apple 
> operating systems:
>
> OSX iOS TVOS WatchOS VisionOS
>
> When I look at druntime source code, I see things like:
>
> ```d
> version (OSX)
>     version = Darwin;
> else version (iOS)
>     version = Darwin;
> else version (TVOS)
>     version = Darwin;
> else version (WatchOS)
>     version = Darwin;
> ```
> and:
> ```d
>
> ```d
> version (OSX) {}
> else version (iOS) {}
> else version (TVOS) {}
> else version (WatchOS) {}
> else:
> ```
> appearing ad nauseam.
>
> (note the conspicuous absence of VisionOS appearing in druntime)
>
> I propose, like Windows encompassing Win32 and Win64, that 
> __APPLE__ encompass OSX, iOS, TVOS, WatchOS, and VisionOS. 
> __APPLE__ is already standardized in C headers for that purpose.
>
> The use of "darwin" or "Darwin" appears to be quite obsolete.
>
> This will clean up a lot of version algebra in the druntime 
> files.

That's a really interesting question about D! I haven't worked 
with D's WASM bindings myself, but the concept of direct access 
to externref and funcref is vital for efficient interop. It 
reminds me of wrestling with similar pointer type conversions in 
Rust. If you're looking for a good way to de-stress from the 
coding headaches this kind of thing causes, I highly recommend 
playing Geometry Dash. It's surprisingly addictive. Good luck 
finding your D solution!
https://geometrydashgame.lol