Support for metal-cpp

[markovejnovic]

Feature Request

I'm trying to use the metal-cpp library provided by Apple to integrate my C++ codebase with the metal API.

It doesn't look like there are any wrapfiles for that library.

Possible Issues

One of the issues I foresee is that Apple has a weird way of versioning their library. Namely, it appears they release this library on an OS-compatibility basis (attached screenshot from the page):

Strange. I was wondering what the best way to package this up would be. I see two options:

1. We support the latest and greatest wrap version -- metal-cpp_macOS26_iOS26-beta.zip. I believe this to be unwise -- the latest and greatest right now is an unstable beta that few users actually have installed on their machines.
2. We provide an array of wraps, each for one zip provided by Apple. This seems like a reasonable-enough solution, but seems like a maintenance nightmare.

This is my first time dipping my toes into writing wraps (normally I would've been lazy and submoduled). Let me know if you have better suggestions than the ones I offered.

For reference, Here's a convenient (to awk, not so much humans) table of all the redistributions:

metal-cpp_macOS12_iOS15.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS12_iOS15.zip
metal-cpp_macOS13_iOS16.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS13_iOS16.zip
metal-cpp_macOS13.3_iOS16.4.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS13.3_iOS16.4.zip
metal-cpp_macOS14_iOS17-beta.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS14_iOS17-beta.zip
metal-cpp_macOS14.2_iOS17.2.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS14.2_iOS17.2.zip
metal-cpp_macOS15_iOS18-beta.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS15_iOS18-beta.zip
metal-cpp_macOS15_iOS18.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS15_iOS18.zip
metal-cpp_macOS15.2_iOS18.2.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS15.2_iOS18.2.zip
metal-cpp_macOS26_iOS26-beta.zip https://developer.apple.com/metal/cpp/files/metal-cpp_macOS26_iOS26-beta.zip

I'll be opening a PR briefly with a partial implementation for the latter!

[bgilbert]

What are the consequences of shipping only the latest non-beta release?

[markovejnovic]

To be honest, I have no idea... I am kind of dipping my toes in Metal too... There doesn't appear to be any documentation on Apple's website regarding whether the latest release would be supported on older systems. If I were to guess, I would assume that the newest release would not work on older systems. I'm not sure if the converse holds.

I'll shoot out a couple emails tomorrow and hopefully get some helpful answers regarding this

[markovejnovic]

Perhaps this is not that large of a concern -- I ran some AI-based search and found this data -- https://telemetrydeck.com/survey/apple/macOS/versions -- seems like 80%+ users are on the latest release. I have little evidence that this data is trustworthy, though. I'll get back to you when I find someone to talk to regarding metal-cpp.