In previous versions of Xcode 6 and 7 with Swift, this syntax would work:
var secureItemValue: Unmanaged? let statusCode: OSStatus = Se
According to this answer you can just remove Unmanaged<> around AnyObject:
Unmanaged<>
var secureItemValue: AnyObject? let statusCode: OSStatus = SecItemCopyMatching(keychainItemQuery, &secureItemValue)