Can you try this on a recent development snapshot from swift.org? The diagnostics might have been improved.

@theblixguy Actually what I get on the most recent snapshot (2019-12-16 (a)) is "Cannot assign to property: 'self' is immutable", which is insane.

@swift-ci create

@xedin says the diagnostic is referring to frame(forAlignmentRect:). The old diagnostic disfavored this overload vs. the frame property; the new one considers both equally valid and ends up talking about the method for some reason.

This is a good starter bug! Here's a reproducer:

import AppKit
let view = NSView()
_ = view.frame.width * Double(0.8)

which currently produces:

error: value of type '(NSRect) -> NSRect' (aka '(CGRect) -> CGRect') has no member 'width'
_ = view.frame.width * Double(0.8)
    ~~~~~~~~~~ ^~~~~

A simpler case without AppKit:

struct Rect {
  let width: Int
  let height: Int
}

class Frame {
  func rect(width: Int, height: Int) -> Rect {
    Rect(width: width, height: height)
  }

  let rect: Rect
}

func foo(frame: Frame) {
  frame.rect.width + 10.0
}

error: value of type '(Int, Int) -> Rect' has no member 'width'
  frame.rect.width + 10.0
  ~~~~~~~~~~ ^~~~~

Comment by Vuk (JIRA)

Is this still available? I would like to give it a shot.

vukrado (JIRA User) yes, this is still available! Please feel free to ask questions if you need help.

Comment by Vuk (JIRA)

Sounds good thank you @hborla! Can I go ahead and assign myself to the issue?

vukrado (JIRA User) yes, please assign to yourself!

Has been fixed by #29795 vukrado (JIRA User) Thank you for the patch!