To fix 2, add '-fno-rtti' to the args: https://gcc.godbolt.org/z/zMdfx71qE https://gcc.godbolt.org/z/zMdfx71qE Unfortunately, gcc does not seem to devirtualize

To fix 2, add '-fno-rtti' to the args: https://gcc.godbolt.org/z/zMdfx71qE https://gcc.godbolt.org/z/zMdfx71qE Unfortunately, gcc does not seem to devirtualize in your example