[SoM] escaping attribute may only be used in function parameter position

[chamons]

This originally used NSImage instead of NSObject but it fails just the same

import AppKit

public extension Array where Element : NSObject {

  public func gradient(_ transform: ((_ gradient: inout CAGradientLayer) -> CAGradientLayer)? = nil) -> CAGradientLayer {
    var gradient = CAGradientLayer()
    return gradient
  }
}

Error (Fatal): SwiftRepro-Array-Extension0.swift:7:40: error: @escaping attribute may only be used in function parameter position
    transform: UnsafePointer<Optional<@escaping (_: UnsafeMutablePointer<CAGradientLayer>, 
                                      ~^~~~~~~~~
                                      
SwiftRepro-Array-Extension0.swift:7:40: error: @escaping attribute may only be used in function parameter position
    transform: UnsafePointer<Optional<@escaping (_: UnsafeMutablePointer<CAGradientLayer>, 
                                      ~^~~~~~~~~
                                      
SwiftRepro-Array-Extension0.swift:7:40: error: @escaping attribute may only be used in function parameter position
    transform: UnsafePointer<Optional<@escaping (_: UnsafeMutablePointer<CAGradientLayer>, 
                                      ~^~~~~~~~~
                                      
SwiftRepro-Array-Extension0.swift:11:17: error: 'T0' is not a subtype of 'NSObject'
    return this.gradient(transform.pointee);
           ~~~~~^~~~~~~~
 (Exception)

[chamons]

Possible duplicate \ simplification of bits of https://github.com/xamarin/maccore/issues/692 ?

[chamons]

Hue.framework