Ambiguous reference to member Swift 3

Question

I am migrating my project from Swift 2.3 to Swift 3. And having difficulty as expected.

Here is a function which is being used for OAuth, using OAuthSwift. I have tried to convert

class func OAuthSwiftAuthorization(inViewController viewController: UIViewController, withOAuthInfo info:FitnessTracker, successHandler:@escaping MyOAuthNewSuccessHandler, failure: @escaping ((_ error: NSError) -> Void)) {

    let oauthswift = OAuth2Swift(
        consumerKey:    info.consumerKey,
        consumerSecret: info.consumerSecret,
        authorizeUrl:   info.authorizeUrl,
        accessTokenUrl: info.accessTokenUrl,
        responseType:   info.responseType
    )

    oauthswift.authorizeURLHandler = SafariURLHandler(viewController: viewController, oauthSwift: oauthswift)
    oauthswift.accessTokenBasicAuthentification = true
    oauthswift.allowMissingStateCheck = true

    oauthswift.authorize(withCallbackURL: URL(string: info.callBackUrl)!, scope: info.scope, state: info.state, success: { (credential, response, parameters) in

             successHandler(credential, response, parameters)
    }) { (error) in

        failure(error: error)
        print(error.localizedDescription)
    }
}

But I am getting an error at

oauthswift.authorize(withCallbackURL: URL(string: info.callBackUrl)!, scope: info.scope, state: info.state, success: { (credential, response, parameters) in

Error states

Ambiguous reference to member 'authorize(withCallbackURL:scope:state:parameters:headers:success:failure:)'

Here is the working code from Swift 2.

    oauthswift.authorizeWithCallbackURL(
        URL(string: info.callBackUrl)!,
        scope: info.scope, state:info.state,
        success: { credential, response, parameters in

            successHandler(credientials: credential, response: response, params: parameters)
        },
        failure: { error in

            failure(error: error)
            print(error.localizedDescription)
        }
    )

UPDATE:

Error does not appear unitil I type success and faliure handelrs. This complies fine:

        oauthswift.authorize(withCallbackURL: URL(string: info.callBackUrl)!, scope: info.scope, state: info.state, success: { (credential, response, parameters) in
        // successHandler(credential, response, parameters)
    }) { (erorr) in
        // failure(error: error
    }

So Please guide me Thanks.

Answer 1

I think the problem is caused by some shortcomings of Swift's type inference in combination with closures. You could try one of the following:

Either don't use trailing closures, e.g.

oauthswift.authorize(withCallbackURL: URL(string: info.callBackUrl)!, scope: info.scope, state: info.state, success: { (credential, response, parameters) in

         successHandler(credential, response, parameters)
}, failure: { (error) in

    failure(error: error)
    print(error.localizedDescription)
})

or provide an explicit type for error, e.g.

 oauthswift.authorize(withCallbackURL: URL(string: info.callBackUrl)!, scope: info.scope, state: info.state, success: { (credential, response, parameters) in

         successHandler(credential, response, parameters)
 }) { (error: Error) in

     failure(error: error)
     print(error.localizedDescription)
 }