What? My understanding was that utf8 was crafted specifically so that the only null byte in it was literally NUL. That all normal human language described by a utf8 string will never contain a NUL. They're comparable to C strings in that way, where it can be used safely as an end of string marker. If you have embedded NULs, it's not really utf8, is it?

They're not though. While having an explicit length is great, p-strings means the length is the first item of the data buffer, which is just awful, and why Pascal was originally limited to 255 byte strings.

Rust or C++ use record-strings, where the string type is a "rich" stack-allocated structure of (*buffer, length[, capacity], …) rather than just a buffer/pointer.