On Tue, 21 Jul 2020 at 02:28, Marek Polacek <pola...@redhat.com> wrote:
>
> P1975R0 tweaks the static_cast wording: it says that "An expression e can be
> explicitly converted to a type T if [...] T is an aggregate type having a
> first
> element x and there is an implicit conversion sequence from e to the type of
> x." This already works for classes, e.g.:
>
> struct Aggr { int x; int y; };
> Aggr a = static_cast<Aggr>(1);
>
> albeit I noticed a -Wmissing-field-initializer warning which is unlikely to be
> helpful in this context, as there's nothing like static_cast<Aggr>(1, 2)
> to quash that warning.
>
> However, the proposal also mentions "If T is ``array of unknown bound of U'',
> this direct-initialization defines the type of the expression as U[1]" which
> suggest that this should work for arrays (they're aggregates too, after all).
> Ville, can you confirm that these
>
> int (&&r)[3] = static_cast<int[3]>(42);
> int (&&r2)[1] = static_cast<int[]>(42);
>
> are supposed to work now? There's no {} variant to check. Thanks.
I don't know what it means to cast something to an array; doesn't that create
an array prvalue? Is that a thing?
