[zamalek]

You can re-interpret the struct to a pointer (length would simply be truncated). Apart from that there wouldn't be any benefit: the pointer and length would be aligned no matter which position they take (on x86 and amd64 at the very least).

[c-smile]

"re-interpret the struct to a pointer (length would simply be truncated)."

Wrong. It will be pointer-to-pointer.

Reinterpretation (to treat struct as a pointer to C string) is only possible if you have something like this:

    struct BSTR {
      size_t length;
      WCHAR  chars[N]; // N is length + 1     
    };

and you return pointer to chars[0]. This is so called Basic string - BSTR is a WCHAR* pointer to memory location prepended by string length field.

[zamalek]

That's not what I was going after. You can treat the memory location (where the structure resides) as a pointer, plan and simple, nothing more fancy than what I said.