They bring up editors that deal with large amounts of text and how they have to use special data structures to handle editing with efficiency. But their solution seems to be to complicate every string with these rather than use them in these specialized circumstances. The value of the null-terminated string is its utter simplicity. For passing as an argument, it's just a pointer. For allocating it's just a single block of memory. For most uses it's just a little bit of text.