Now that default arguments are always emitted into the client, it'd be correct to fix this…but the warning happens in Sema, before we've looked at what the default argument value is. Maybe we should record the type of the default argument before coercion or something?

@swift-ci create

I just ran into this today. I wrote a method like this:

extension Sequence where Element: BinaryInteger {
  func checksum(using f: (Element,Element)throws->Element = (^)) rethrows -> Element {
    return try self.reduce(0){ try f($0, $1) }
  }
}

And I wanted to call it like this:

extension Sequence {
  func checksum(transform: (Element)->Int) -> Int {
    self.lazy.map(transform).checksum()
    // error: Call can throw but is not marked with 'try'
  }
}

But that code does not compile, so I had to include the xor operator as an argument anyway.

Is there an expected timeline for when this might get fixed?