RFC: C++0x ABI PATCH to decltype handling

[Mark Mitchell]

On 2/22/2011 5:48 PM, Jason Merrill wrote:

> Discussion on the ABI mailing list eventually came to the conclusion
> that my attempts to define a subset of decltypes that can be folded away
> was misguided, and we should just directly mangle all dependent
> decltypes.  The consequence of this is that we can't fold them away
> internally either.

> Any comments?

I hate breaking backwards compatibility, but even I find it hard to
argue against this change.  In general, I think that requiring lexical
(rather than semantic) equivalence between template declarations and
definitions makes a ton of sense, and I do agree that there's probably
very little code out there that's depending on the old behavior.

Maybe we ought to decide that -fcxa-abi=latest (sp?) is the default, and
that immediately after each release we bump the version, so that every
compiler has a new version number, and users can always go backwards if
they really care?  (I know that EDG has done something similar to that.)

Thank you,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713