On 9/16/23 18:00, Patrick Palka wrote:
On Sat, 16 Sep 2023, Jason Merrill wrote:
On 9/15/23 13:55, Patrick Palka wrote:
This corrects decltype of a (class) NTTP object as per
[dcl.type.decltype]/1.2 and [temp.param]/6 in the type-dependent case.
In the non-dependent case (nontype-class8.C) we resolve the decltype
ahead of time, and finish_decltype_type already made sure to drop the
const VIEW_CONVERT_EXPR wrapper around the TEMPLATE_PARM_INDEX.
Hmm, seems like dropping the VIEW_CONVERT_EXPR is wrong in this case? I'm not
sure why I added that.
Ah sorry, my commit message was a bit sloppy.
In the non-dependent case we resolve the decltype ahead of time, in
which case finish_decltype_type drops the const VIEW_CONVERT_EXPR
wrapper around the TEMPLATE_PARM_INDEX, and the latter has the
desired non-const type.
In the type-dependent case, tsubst drops the VIEW_CONVERT_EXPR
because the substituted class NTTP is the already const object
created by get_template_parm_object. So finish_decltype_type
at instantiation time sees the bare const object, which this patch
now adds special handling for.
So we need to continue dropping the VIEW_CONVERT_EXPR to handle the
non-dependent case.
Aha. The patch is OK, then.
Jason
