Philip Warner <pjw@rhyme.com.au> writes:
> None, but it will be compatible with itself (the most we can hope for), and
> will work even if shifting is not supported for off_t (how likely is
> that?). I agree shift is definitely the way to go if it works on arbitrary
> data - ie. it does not rely on off_t being an integer. Can I shift a struct?
You can't. If there are any platforms where in fact off_t isn't an
arithmetic type, then shifting code would break there. I am not sure
there are any; can anyone provide a counterexample?
It would be simple enough to add a configure test to see whether off_t
is arithmetic (just try to compile "off_t x; x <<= 8;"). How about#ifdef OFF_T_IS_ARITHMETIC_TYPE // cross-platform
compatible use shifting method#else // not cross-platform compatible read or write bytes of struct in storage
order#endif
regards, tom lane
