Swift 3.0: Data to JSON [String : Any]

Question

Evening, I'm trying to creating an APIClient, but I'm having a problem with a warning: APIClient.swift:53:81: Cast from 'Data' to unrelated type '[String : Any]' always fails

In this code I'm trying to convert Data into JSON as a dictionary [String : Any].

I guess the compiler can't know if this cast could or could not be possible so it throws the error, but I'm pretty sure it will work. So how can I avoid this warning or how can I write safer code?

do {
  let json = try JSONSerialization.data(
    withJSONObject: data!,
    options: []
  ) as? [String : Any]
  completion(json, HTTPResponse, nil)
} catch let error {
  completion(nil, HTTPResponse, error)
}

Answer 1

The right method is:

do {  
    let json = try JSONSerialization.jsonObject(with: data!, options: []) as? [String : Any]
} catch {
    print("errorMsg")
}

Thanks to Eric Aya