Re: [PATCH] Various pages: SYNOPSIS: Use VLA syntax in function parameters

Martin Uecker
2022-11-12T07:24:55Z

Am Samstag, den 12.11.2022, 01:09 +0000 schrieb Joseph Myers:
> On Fri, 11 Nov 2022, Martin Uecker via Gcc wrote:
>
> > > Even a compiler extension requires the level of detail of specification
> > > that you get with a WG14 paper (and the level of work on finding bugs in
> > > that specification), to avoid the problem we've had before with too many
> > > features added in GCC 2.x days where a poorly defined feature is "whatever
> > > the compiler accepts".
> >
> > I think the effort needed to specify the feature correctly
> > can be minimized by making the first version of the feature
> > as simple as possible.
>
> The version of constexpr in the current C2x working draft is more or less
> as simple as possible. It also went through lots of revisions to get
> there. I'm currently testing an implementation of C2x constexpr for GCC
> 13, and there are still several issues with the specification I found in
> the implementation process, beyond those raised in WG14 discussions, for
> which I'll need to raise NB comments to clarify things.

constexpr had no implementation experience in C at all and
always suspected that C++ experience should somehow count is
not really justified.

> I think that illustrates that you need the several iterations on the
> specification process, *and* making it as simple as possible, *and*
> getting implementation experience, *and* the implementation experience
> being with a close eye to what it implies for all the details in the
> specification rather than just getting something vaguely functional but
> not clearly specified.

I agree. We should work on specification and on prototyping
new features in parallel.

Martin