[v3 PATCH] Use single-visitation in variant assignment and swap.

[Ville Voutilainen]

On Mon, 1 Apr 2019 at 11:50, Ville Voutilainen
<ville.voutilainen@gmail.com> wrote:
> in it makes it trivial and I don't
> need to worry about the validity of the branch taken, since it's not
> instantiated. This is a new

I mean the branch *not* taken. :)