AaronBallman wrote: The rules between C and C++ aren't quite the same. C prohibits auto-increment from changing from signed to unsigned. C23 6.7.2.2p12:
> A signed integer type is chosen if the previous enumeration constant being > added is of signed > integer type. An unsigned integer type is chosen if the previous enumeration > constant is of > unsigned integer type. If there is no suitably sized integer type described > previously which > can represent the new value, then the enumeration has no type which can > represent all its > values. whereas C++ allows changing from signed to unsigned. C++23 [enum]p5: > Otherwise the type of the enumerator is the same as that of the preceding > enumerator unless the incremented value is not representable in that type, in > which case the type is an unspecified integral type sufficient to contain the > incremented value. If no such type exists, the program is ill-formed. Curiously though, GCC seems to implement the rules backwards from what I'd expect: https://godbolt.org/z/abGvj9Tn4 but that might be for backwards compatibility as they do that in C17 mode as well. One interesting thing to test is `-pedantic` mode to make sure we don't get this: https://godbolt.org/z/K4K1E3GEx https://github.com/llvm/llvm-project/pull/78742 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
