https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123752
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to John Drouhard from comment #6)
> (In reply to Boris Staletic from comment #3)
> > > test.cpp:7:3: error: uncaught exception of type 'std::meta::exception';
> > > 'what()': 'neither name nor bit_width specified'
> >
> > That's expected. It's a later change in the proposal that clang-p2996 fork
> > has not implemented.
> >
> > An empty name implies an anonymous bit field. An empty bit_width implies a
> > non-bit field.
>
> Ok, that seems like an invalid assumption.
No, it is a requirement of the standard.
> An empty name doesn’t imply an
> anonymous bit field. How would you define an aggregate with fields you don’t
> need to access by name but aren’t bit fields? For instance, defining a
> struct, or union you’d pair with an index and only access the fields by that
> index (to implement tuple or a tagged union/variant)?
By using placeholder name? I.e. {.name="_"}
