=∅ (null check) debug operator

Nil Evaluate Operator.swift

infix operator =∅ {}
func =∅<T> (v:T?, ref: (file: String, line: Int)) -> T? {
#if debug
  var unwrap = false
  if let _ = v { unwrap = true }
  let source = ref.file
    .characters
    .split("/")
    .map{String($0)}
    .last ?? ""
  let outcome = "unwrap(\(unwrap ? "success" : "failure"))"
  print("\(source)(\(ref.line)), \(outcome), value: \(v)")
#endif
  return v
}

let dict: [String: Any] = ["Apple": "one", "Google": "two", "Microsoft": 3]
guard
  let apple = dict["Apple"] as? String =∅ (#file, #line),
  let google = dict["Google"] as? String =∅ (#file, #line),
  let microsoft = dict["Microsoft"] as? String =∅ (#file, #line)
  else {
     fatalError("unwrap failed")
}
print(apple, google, microsoft)

// Example output:
//   playground218.swift(114), unwrap(success), value: Optional("one")
//   playground218.swift(115), unwrap(success), value: Optional("two")
//   playground218.swift(116), unwrap(failure), value: nil