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Re: [ub] Remove undefined behavior from the preprocessor

From: Lawrence Crowl <Lawrence_at_[hidden]>
Date: Wed, 16 Oct 2013 16:49:23 -0700
On 10/14/13, Gabriel Dos Reis <gdr_at_[hidden]> wrote:
> > On 10/14/2013 03:18 PM, Gabriel Dos Reis wrote:
> > > Revision based on feedback attached.
> > > - UCN token splicing is made conditionally supported with
> > > implementation defined semantics, instead of just ill-formed
> > > as proposed earlier.
> >
> > Aren't there just two options: Either this becomes a UCN by token
> > splicing, or it stays a sequence of individual characters? Can't
> > we just say that?
> A third option is "ill-formed". I don't think we should get down to
> that level of detail here. I would rather leave it to implementations
> and tools whether they want to support clean mode (diagnose), garbage
> mode (individual characters), or make sense of it
> (implementation-defined semantics.)

For the preprocessor, I would rather not see undiagnosed differences in
behavior. Wouldn't it be best to simply poll the vendors and see if
they are okay with standardizing on "UCN from splicing"?

Lawrence Crowl

Received on 2013-10-17 01:49:26