Sure, but the thread here was about the forced NUL-terminator in std::string and the costs associated with that. If you want a NUL-terminator (e.g. for use with a C API) then you have to pay the copy (and in the general case, allocation) cost for substrings no matter how your internal strings look (unless you can munge the original string) and std::string is exactly the right abstraction for you.
But yeah, it would be nice if the kernel and POSIX APIs had better support for pointer+size strings.
But yeah, it would be nice if the kernel and POSIX APIs had better support for pointer+size strings.