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. 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. -- Joseph S. Myers jos...@codesourcery.com
