Forgive me, but I don’t see how this is ambiguous, ambiguous with which other version of when?

Hello @mxcl
For instance, in

let p1 = Promise<Void>(error: Error.test)
let p2 = after(.milliseconds(100)).done { throw Error.straggler }
let p3 = after(.milliseconds(200)).done { throw Error.straggler }

when(fulfilled: p1, p2, p3).catch { error -> Void in
    XCTAssertTrue(Error.test == error as? Error)
    ex1.fulfill()
}

As I can see in the debugger func when<U: Thenable, V: Thenable, W: Thenable>(fulfilled pu: U, _ pv: V, _ pw: W) -> Promise<(U.T, V.T, W.T)> is using here. But public func when<U: Thenable>(fulfilled promises: U...) -> Promise<Void> where U.T == Void is suitable here as well:

(when(fulfilled: p1, p2, p3) as Promise<Void>).catch { error -> Void in
    XCTAssertTrue(Error.test == error as? Error)
    ex1.fulfill()
}

Maybe there is a rule why func when<U: Thenable, V: Thenable, W: Thenable>(fulfilled pu: U, _ pv: V, _ pw: W) -> Promise<(U.T, V.T, W.T)> has a higher priority.

Oh ok. I’m not sure it matters per se, but why not.