Comment by toast0

I don't think you could do it transparently, because it's expected to pass the tail of a character array by doing &s[100] or s + 100, etc. I don't think that would be easy to catch all of those and turn them into a string fragment reference.

From c++ class, std::string was easy enough to use everywhere, and just foo.c_str() when you needed to send it to a C library. But that may drags in a lot of assumptions about memory allocation and what not. Clearly, we don't want to allocate when taking 6 minutes to parse 10 megs of JSON! :)