https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80886
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to steveren from comment #0)
> Has this behaviour changed deliberately?
Yes, because the standard forbids it.
As Andrew said, the __builtin_constant_p part (and what the docs say about it)
is irrelevant because the (void *) 0x1000 expression is what gives an error.
> As I say, it is contrary to the
> Standard, but it would be disappointing to lose such a useful extension.
I think it would be better to add support to C++ for "pointer literals", I've
been talking with a few people about proposing that for the standard.
That would allow you to create constexpr pointers from literal integers, but
still disallow arbitrary reinterpret casts between them.
Closing as G++ is correct to disallow this.
