-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Bruno Haible wrote: > Ben Pfaff wrote: >> ISO C says that NULL can be defined as 0, without a cast to void >> *, and it is always defined that way in C++. > > The latter statement is not true. ISO C++ 18.1.(3) says: > > "The macro NULL is an implementation-defined C++ null pointer constant > in this International Standard (4.10)." > with footnote: > "Possible definitions include 0 and 0L, but not (void*)0." > > and g++ defines NULL to __null. The differences between NULL and 0 in g++ > are least: > - sizeof (NULL) == sizeof (void*), > - sin (NULL) gives a warning, sin (0) does not.
So it could be something besides 0 or 0L. But I'm pretty sure Ben's point was that it is not safe to assume that using NULL, addresses those argument-passing problems, as you claimed (that is, it may be defined as just 0 or another type that is not compatible with (void*)). To be portable, it must be cast when passed as a vararg param. - -- Micah J. Cowan Programmer, musician, typesetting enthusiast, gamer... http://micah.cowan.name/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHEWfe7M8hyUobTrERCAKVAKCKw1ES8cc4hLKbBBrV0VThXc3qVgCfRlbl udvr5wlLCmtfV+7TNgO6Ans= =wg6o -----END PGP SIGNATURE-----
