Swift 3.0：如果没有更多上下文，表达式的类型是否模棱两可？

private func makeRequest<T where T:MappableNetwork>(method method: Alamofire.Method, url: String,
                         parameters: [String: AnyObject]?, keyPath: String, handler: NetworkHandler<T>.handlerArray) -> Request {

    let headers = [
        "Authorization": "",
        ]

    return Alamofire
        .request(method, url, parameters: parameters, encoding: .URL, headers: headers)
        .validate()
        .responseArray(keyPath: keyPath) { (response: Alamofire.Response<[T], NSError>) in
            if let error = response.result.error {
                if let data = response.data {
                    let error = self.getError(data)
                    if error != nil {
                        handler(.Error(error: error!))
                        return
                    }
                }
                handler(.Error(error: error))
            } else if let objects = response.result.value {
                handler(.Success(data: objects))
            }
    }
}

我将代码swift 2.x转换为3.x，并且出现错误类型表达式在没有更多上下文的情况下是模棱两可的。