P3412 accounts for an encoding prefix, which is what I would expect so ship
it (to ewg), P3951 is silent on the matter so that should be fixed - by
doing what p3412 does, ie ut"", Ut"", u8t"", utR, etc - and then shipped to
do lewg.

Barry's addresses concatenation (consistent with what the lexer does).

I don't foresee any other sg16 consideration here.

Ultimately we are producing fragments of string literal, and there is not
much room for deviation in terms of encoding or text handling.

There are of course many considerations here but I think these are best
pondered in EWG


cheers!

On Mon, Feb 23, 2026, 05:15 Tom Honermann via SG16 <sg16_at_[hidden]>
wrote:

> SG16 will hold a meeting Wednesday, February 25th, at 19:30 UTC (timezone
> conversion
> <https://www.timeanddate.com/worldclock/converter.html?iso=20260225T193000&p1=1440&p2=tz_pst&p3=tz_mst&p4=tz_cst&p5=tz_est&p6=tz_cet>
> ).
>
> The agenda is:
>
> - P3412R3: String interpolation <https://wg21.link/p3412r3>.
> - P3951R0: String Interpolation with Template Strings
> <https://wg21.link/p3951r0>.
>
> SG16 previously reviewed *P3412R1 <https://wg21.link/p3412r1>* during the 2025-02-26
> SG16 meeting
> <https://wiki.isocpp.org/2025_Telecons:SG16Teleconference2025-02-26>.
> Concerns raised then included interaction with the preprocessor, the phases
> of translation, handling of escape sequences, standalone usability, and
> integration with std::format(). Bengt will present a brief overview of
> the proposal and the updates in the new revisions intended to address prior
> SG16 review feedback.
>
> *P3951R0* is a new paper courtesy of Barry that offers an alternative
> perspective on string interpolation that makes different tradeoffs relative
> to P3412R3.
>
> Please try to set aside time to read both of these papers before the
> meeting as there are many details to consider. Spend some time considering
> possible future use cases (from an SG16 perspective) and the ability for
> each design to evolve to satisfy them.
>
> I don't expect discussion on these papers to conclude at this meeting.
> Plan for 30 minutes of presentation and clarifying questions for each
> paper. We'll then proceed with general discussion. Ideally, discussion
> would lead authors towards a unified/merged design or a determination that
> one proposal or the other is objectively better suited to desired and
> anticipated uses. If consensus for a single design fails to emerge, then
> we'll focus on understanding the points of contention with a goal of
> ensuring LEWG is well informed of the relevant tradeoffs.
>
> Tom.
>
>
> --
> SG16 mailing list
> SG16_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/sg16
> Link to this post: http://lists.isocpp.org/sg16/2026/02/4674.php
>