I don't know if
this issue of the empty base class is important anymore
with current C++ compilers.
This was the only part of this discussion I was smart enough to
understand, so I decided to reply to it. :-)
In G++ 3.0, there is no empty base class penalty. The same will
be true for any IA64 C++ ABI compliant compiler. Modern versions
of the EDG front end (used in KCC, the Intel compiler, the SGI
compiler, the DEC/Compaq compiler, and elsewhere) are capable of
avoiding the penalty. However, I do now know if the vendors were
willing to turn on this feature, since it will break compatibility
with previous versions of their compilers. And, I do not know
whether VC++ is capable of avoiding the penalty.
Irrelevant compilers for computers named after fruit are mentioned
only because I know that the mere presence of this sentence will
get people's adrenalin pumping in New Mexico. :-) Seriously, I
know nothing of whether Metrowerks can do this or not.
It would be great if someone could try out:
struct S { };
struct T : public S { char c; };
int main () { return sizeof (T); }
with KCC. If things are good, the program will return 1; if bad,
some greater value.
-- Mark Mitchell address@hidden
CodeSourcery, LLC http://www.codesourcery.com