On 28/03/2021 23.13, Corentin Jabot wrote:
> We should strike
>> if a splice results in a character sequence that matches the syntax of a /universal-character-name/ <http://eel.is/c++draft/lex#nt:universal-character-name>, the behavior is undefined.
> Both because it matches existing practices (except msvc) and because it follows the flow of the wording. (ucn are replaced in the next phase)
>
> What should happen when a ucn is formed by a preprocessor in phase 4 is less clear to me.
> Given that no compiler do the right thing, it would be sensible that it would be ill-formed https://godbolt.org/z/of4W9dG8h <https://godbolt.org/z/of4W9dG8h>
>
>> If a ' or a " character matches the last category, the behavior is undefined
> That should be ill-formed, which is what all compilers do. I suspect this specific undefined behavior is an artifact of C wording

Those items seem to be wonderful topics for a separate paper,
which needs to go through SG12.

SG12 currently has 14 papers on their plate (excluding those with
the "needs-revision" label), and I don't remember any SG12
teleconference in the past year or so.

Jens