[larusso]

I’m not sure if I/O kit was written in this c++ subset just for speed. There was this controversial at the time. Apple announced MacOS X and said that it won’t be compatible with current software. All partners would need to rewrite the software in Objective-C. This didn’t go over well. Apple back paddelt and introduced “carbon”. An API layer for cpp applications as well as “Core Foundation” an underpinning to the objective-c base Framework “Foundation”. Also the reason why we have Obj-c++. The interesting part is that they managed to get the memory management toll free. Means an object allocated in the c/cpp world can be passed to obj-c without extra overhead.

[comex]

IOKit C++ is running in the kernel, so it's not really related to any of the technologies you mentioned which are all userland-only.

[dcrazy]

Being able to port your existing C++ driver to IOKit instead of rewriting it in Objective-C is a selling point. For some reason people a lot of people seem to dislike writing an Objective-C shell around their C++.

[larusso]

You may underestimate how many drivers had to be shipped and developed by external companies compared to today. For software / hardware companies that was a huge deal.