That's something C's type system doesn't check for. If you want protection for this case, use C++ or any other higher-level language instead.

Well to be pedantic C++'s type system doesn't check for that either it just passes around a size_t and char *.

I was referring to std::string, which is what you should be using if you're handling textual data natively.

The implementation of std::string is 99.999% of the time struct { char *s; size_t len; }, which has nothing to do with an actual type.

And it's even possible to use std::string as a buffer for binary data including NULs. I won't recommend it, but it works.

I'd suggest using a std::vector of byte-sized integers for clarity, though there's nothing wrong from a standards point in using a std::string.