Function subscription_view 

pub fn subscription_view(
    content: &ViewHandle,
    complete_immediately: bool,
    action: impl Fn(i64) + 'static,
) -> ViewHandle

SubscriptionView(content:publisher:action:) — onReceive as a view.

The same thing super::on_receive does as a modifier, and with the same publisher: Combine.Empty<Int, Never>, which is the one publisher that can be built without a Foundation object behind it. complete_immediately is Empty’s only stored property — true finishes at once, false never publishes anything.

PublisherType comes first in SubscriptionView<PublisherType, Content>, so the metadata and witness tables go in that order too. The labels read content:publisher: and the arguments follow the labels, which is the opposite order from the generic parameters — worth getting from the IR rather than from the signature.