It doesn't have to be an issue, but users should be aware that the default string type should be avoided in hot paths, which can be cumbersome. The reason it'll

It doesn't have to be an issue, but users should be aware that the default string type should be avoided in hot paths, which can be cumbersome. The reason it'll be slow is because iterating linked lists involve a lot of pointer chasing, which implies bad behavior on x86 and worse behavior on CPUs that don't have a data prefetcher.