Why is python not written in C++ ?

[Roy Smith]

In article <mailman.1666.1281075732.1673.python-list at python.org>,
 David Cournapeau <cournape at gmail.com> wrote:

> > Yes, there are a few corner cases where valid C syntax has different
> > semantics in C and C++. Â But, they are very few. Â Calling C++ a superset
> > of C is essentially correct.
> 
> This is only true if you limit yourself to C89 (as python seems to
> do). If  you start using C99 (and lot of people do, if only because
> they don't realize it because gcc is quite relax about it), then
> almost no non trivial C code is valid C++ in my experience.

I'm not following you.  If anything, C99 makes C closer to C++.  Can you 
give me some examples of valid C99 which is not also valid C++?