C2x features status

[Joseph Myers]

On Fri, 21 Oct 2022, Florian Weimer wrote:

> > while typeof was enabled by default for -std=gnu* anyway 
> > in previous releases so is a lower risk.
> 
> Do the semantics of typeof change to align with C++, so that typeof
> (int) becomes invalid?

No.  Both typeof (expr) and typeof (type) are valid.

The changes to make typeof (expr) consistently avoid returning a qualified 
or atomic type when passed an rvalue argument (while preserving qualifiers 
on lvalues) mostly went into previous releases, but I found and fixed a 
few more cases when implementing standard typeof (and all those fixes are 
unconditional).

typeof in C2x mode does not treat const or noreturn function attributes as 
part of the type of a function or function pointer, unlike typeof in 
previous modes and __typeof even in C2x mode.

-- 
Joseph S. Myers
joseph@codesourcery.com