Fully agree with Tom.

- Victor

On Wed, Oct 23, 2024 at 8:03 AM Tom Honermann via SG16 <
sg16_at_[hidden]> wrote:

> Concerns about std::mbstate_t fall under our purview. I expect LEWG to
> look to us for a recommendation of how to handle features that concern it.
>
> Tom.
>
> On 10/23/24 2:11 AM, Jens Maurer via SG16 wrote:
> > I think it is off-topic for SG16 to discuss this proposal at all.
> > There are no encoding concerns beyond those already answered for
> > std::format, and what the components of a std::fpos<T> are and
> > which sequence of characters is used to represent it and whether
> > you can (hypothetically) parse the representation to recover a
> > std::fpos<T> are all good questions --- that belong to LEWG, not SG16.
> >
> > And a data point: The convertibility requirement for std::fpos to
> > std::streamoff (C++98) predates the introduction of explicit conversion
> > operations (C++11), thus the only way to reasonably satisfy the explicit
> > conversion requirement was for implementations to provide an implicit
> > conversion.
> >
> > Jens
> >
> >
> > On 23/10/2024 02.06, 梁家铭 via SG16 wrote:
> >> Hi Corentin,
> >>
> >> The first version of draft (D3374R0) is to format the `fpos` as an
> integer directly, which can be confirmed by Victor. The reason why I
> finally add the state type is that Tom reminds me that it's not proper to
> neglect such a basic component by default and I think that really makes
> sense. This also makes me reflect that it's possibly not robust for stream
> to only output the integer, and that's why `.offset` is not thought as the
> solution. There is no difference for me to cast explicitly or call
> `.offset`.
> >>
> >> In today's talk, I'd like to share something about:
> >> + briefly cover what mbstate_t should do, as you may be already
> familiar with;
> >> + why C++ programmers generally think it's enough to use the integer,
> as a result of illusion from the implementations of streams that do text
> encoding;
> >> + we could provide such facility in the standard library for those
> programmers who concern the state, as long as we think mbstate_t is not a
> deprecated feature.
> >>
> >> For the formatting specification, there could be some better
> representations if `(pos, mbstate)` is not considered as a good one or even
> not the default one, and I'd like to discuss with you :). I know that
> mbstate_t couldn't be expected to be formatted in any meaning way, but it's
> enough to make it recoverable by the implementation. For me doing a
> round-trip is possibly the most thing we could do in the standard.
> >>
> >> Thanks for the feedback,
> >> Liang Jiaming
> >>
> >>
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