The ABI breaks when you change string implementation to use an optimization for small strings. Therefore you can't optimize them without breaking ABI. C has no

The ABI breaks when you change string implementation to use an optimization for small strings. Therefore you can't optimize them without breaking ABI. C has no strings. The optimization was considered vital enough for a rare break to actually happen but there are multiple such clear wins that cannot be implemented because of ABI stability. Sometimes it's a major pain to have to keep piling the cruft on.