* If you're appending data to a string, and the variable-length increases by a byte, will you have to memmove() the entire existing string down 1 byte?

* Is every programmer responsible for detecting this condition?

* (This will make manual string manipulation very complicated and dangerous.)

* Suppose you're concatenating two strings, such that the sum of the lengths requires an additional byte. This could cause a buffer overflow. How would a strcat() function avoid causing a buffer overflow here?

* Does every string need a maximum-length counter too?

* Can you access a random element in the string without having to dereference and decode the length?

On the other hand, if you use a constant-sized length,

* What happens when you overflow the maximum length?

* Can you erroneously create a shorter string by appending text?

* How should string libraries handle this condition? By abort()ing? By returning a special error code? Does every string manipulation need to be wrapped in an if() to detect the special error? How should the programmer handle this condition?

In either case,

* Can you tokenize a string in-place?

* Can an attacker read a program's entire address space by finding an address that begins 0xffffffff and treating it as a string?