Le mar. 29 sept. 2026 à 10:31, Jens Maurer via SG16 <sg16_at_[hidden]>
a écrit :

> The model is that trigraphs are mapped in phase 1 (which is
> implementation-defined),
> and the implementation is simply considered to use a (rather strange)
> source file
> encoding. Which is conforming.
>
> Whether that kind of allowance jeopardizes the portability promises of C++
> is another question.


Le lun. 28 sept. 2026 à 23:09, Corentin Jabot via SG16 <
sg16_at_[hidden]> a écrit :

> The model is that we can magically map the trigraphs that would appear
> outside of string literal in later phases. Which is even implementable
> given the fact no one actually implement distinct phases. It's a
> reasonable-ish justification to support trigraphs without warnings.


Le mar. 29 sept. 2026 à 23:36, Tom Honermann via SG16 <sg16_at_[hidden]>
a écrit :

> It sounds like the digraph model (since character and string literals
> aren't affected), but using the character sequences from trigraphs.
>

Presumably the wording of phase 1 allows for a stateful encoding (a
compiler could allow for ISO 2022 or SCSU source files).

But then that should allow for an even stranger encoding where the byte
corresponding to " in ASCII (or EBCDIC), as well as some other byte
sequences, are simultaneously printing characters and shift functions,
controlling a mode D, and where the byte sequence corresponding to %: in
ASCII (or EBCDIC) represents U+0023 in mode D, and represents the sequence
U+0025, U+003A outside of mode D.

Admittedly raw string literals make that hypothetical encoding extremely
weird.

Best regards,

Robin Leroy