[zZorgz]

Likely too much friction. Native environments benefit from using the expected IDE and tooling integration to build UI apps on respective platform. C or C++ is the best common supported language, and they didn't even like that.

Also the UI frameworks are being written in said preferred language these days, eg SwiftUI, and adding one additional language could be perceived as a pain.

[eridius]

Apple ships a C++ compiler but you can't use C++ with Apple's platform SDKs. IF you want to use C++ you need to write Obj-C++ glue code to access most of the system frameworks, including UI code.

[zZorgz]

I would look at it differently, i.e, obj-c++ is a valid supported language environment, that makes interopt with C++ pleasant at least compared to other interopt choices. Developers may choose to target Obj-C++ even out of preference.

[pjmlp]

Metal and driver SDKs require C++.

[eridius]

Metal is Obj-C.

[pjmlp]

Then try to write Metal shaders in Objective-C.

[eridius]

Metal shaders != Metal API. Metal API is Obj-C. Metal shaders are written in MSL (Metal Shading Language). C++ is still not involved, though MSL is admittedly based on C++.

[pjmlp]

Metal API ⊇ Metal Shaders, it is useless without them.

https://developer.apple.com/metal/Metal-Shading-Language-Spe...

"The Metal programming language is a C++14-based Specification with extensions and restrictions. Refer to the C++14 Specification (also known as the ISO/IEC JTC1/SC22/WG21 N4431 Language Specification) for a detailed description of the language grammar. This section and its subsections describe the modifications and restrictions to the C++14 language supported in Metal."

Also, the MSL and Objective-C compilers are built on top of LLVM, written in C++.