Strange behaviour in C++...

[Joe Buck]

Jeff writes:

> > Just a note, thunks may be on their way out.  I'm hearing more and
> > more people talk about the evils of thunks, particularly for high
> > end processors.

Mike Stump writes:
> Forget about talk, talk is cheap.  What I have _never_ seen, are real
> performance numbers for real applications and/or micro benchmarks,
> that show what the numbers are. 

I'd like to second Mike's comments.  What you may be overlooking, Jeff, is
that the vast, vast majority of C++ objects are plain single inheritance,
which means that no thunks are needed and the non-thunks implementation
needs twice as much data space for the virtual function tables.  So it
simply does not matter if thunks are slower, since thunks are rarely
called.  It is a time-space tradeoff where the excess time cost is rare.