What's the correct way to discriminate between the two cases?
Currently I'm using:
#if _runtime(_ObjC) print("We're probably using the proprietary implementation of XCTest") #elseif _runtime(_Native) print("We're probably using the open source implementation of XCTest") #else #error("Unrecognized runtime") #endif
But this seems indirect, and perhaps error-prone. E.g. can a person " crisscross" things and use the open source XCTest on a Mac?