swift 3 method in objective-c fails with no visible @interface for 'MySwiftClass' declares the selector 'addX:andY'

Question

we are trying to reference swift methods inside an objective-c implementation.

Swift 3 Class:

import Foundation
@objc class MySwiftClass: NSObject {         


        

Answer 1

In my case I had forgotten to add:

#import "MyProject-Swift.h"

Into the obj c file.