Interesting; I was wondering if they had added some magic feature to Clang to enable Objective-C in pure C++ mode, but no, it really is C++. It just directly calls the Objective-C runtime functions like sel_registerName, objc_lookUpClass, objc_msgSend, etc. The expensive lookups like sel_registerName are performed in initializers of global variables, whereas for 'real' Objective-C code the dynamic linker does essentially the same job itself. I believe this has the disadvantage that unused selectors can't be fully optimized out, as C++ doesn't allow removing global initializers even if the global in question is unused. Therefore, any program that includes this library will, at initialization time, look up all ~1100 selectors defined in the library, regardless of which ones the program actually uses. But besides that, this approach may have equal performance to native Objective-C.
Also - throwing a zip file over the fence, really? Can't you put it on GitHub?
Also - throwing a zip file over the fence, really? Can't you put it on GitHub?