[Pitch N+1] Typed Throws

[pyrtsa (Pyry Jahkola)]

@Vaida12345

func foo<E1: Error, E2: Error>(handler1: () throws(E1) -> Void, handler2: () throws(E2) -> Void) throws {
    handler1()
    handler2()
}

[…]

Is there a way to change this so that it would only throw when at least one of its handlers throws?

I don't think it's possible in today's Swift, but with language evolution a limited form could be possible in the future even without sum types if errorUnion(E1, E2) from the proposal was turned into a proper type expression.

It was discussed around here: [Pitch] Typed throws in the Concurrency module - #28 by Douglas_Gregor