 
 public // @testable
 struct _BridgeStorage<
-  NativeType: AnyObject, CocoaType: AnyObject
+  NativeType: AnyObject,
+  CocoaType/*: AnyObject*/ // FIXME: Workaround for <rdar://problem/18992875> Couldn't find conformance
 > {  
   public // @testable
   typealias Native = NativeType

  public // @testable
  init(_ native: Native, bits: Int) {
    _sanityCheck(_usesNativeSwiftReferenceCounting(NativeType.self))
    _sanityCheck(!_usesNativeSwiftReferenceCounting(CocoaType.self))
    _sanityCheck(0..<3 ~= bits,
        "BridgeStorage can't store bits outside the range 0..<3")


  public // @testable
  init(_ cocoa: Cocoa) {
    _sanityCheck(_usesNativeSwiftReferenceCounting(NativeType.self))
    // FIXME: Workaround for <rdar://problem/18992875> Couldn't find conformance
    // _sanityCheck(!_usesNativeSwiftReferenceCounting(CocoaType.self))
    rawValue = _makeObjCBridgeObject(
      Builtin.reinterpretCast(cocoa) as AnyObject)
  }
  
  public // @testable
