On Thu, 18 Oct 2018, Uecker, Martin wrote: > Most of the restrictions for these types would be the same > as proposed for your sizeless types. > > Because all these types fall into the same overall class > of types which do not have a size known at compile > time, I would suggest to add this concept to the standard > and then define your vector types as a subclass which > may have additional restrictions (no sizeof) instead > of adding a very specific concept which only works for > your proposal.
And an underlying point here is: Various people are exploring various ideas for C language and library features that might involve extending the kinds of types present in C. Maybe some of the ideas will turn out to be fundamentally flawed; maybe some will work with existing kinds of types rather than needing new kinds of variable-sized types. But since all those ideas are currently under discussion in WG14, the SVE issues should be brought into the exploration process taking place there, with a view to getting a better-defined set of concepts for such types out of that process than from considering just one proposal for concepts for one set of requirements in the context of one implementation. Once that discussion has resulted in a more generally applicable set of concepts, experience in implementing that set of concepts - likely various different people implementing them, in different C implementations, with a view to the different use cases they are exploring - could help inform any standardization of such features. -- Joseph S. Myers jos...@codesourcery.com
