Mistake in C++ ABI substitution rules?

[Joe Buck]

> In the past I reported a problem with the way g++ 3.x mangles
> names, related to substitutions.  It does not handle the substitutions
> the way it should (according to the ABI).
> 
> The reponse was that the ABI would not be changed when it
> didn't break anything the way it was.  So yes, it seems that the
> mangling is still compiler specific and the choice is to leave it
> that way.

The possibilility was left open to fix any errors in the ABI for 3.1
(since we have to break compatibility for the standard library anyway),
but we didn't want to break compatibility between 3.0.x releases.

Perhaps the 3.1 release is a good place to fix problems such as the ones
Carlo is pointing out, but I'm not certain.

Does anyone know what other compilers besides gcc purport to implement
the standard ABI, and how they handle the cases Carlo is talking about?