A simple ServiceLocator written in Swift.

ServiceLocator.swift

protocol ServiceLocatorType {
    func getService<T>(type: T.Type) -> T
}

public final class ServiceLocator: ServiceLocatorType {

    public static let instance = ServiceLocator()

    private var serviceRegistry: [String:Any] = [:]

    private init() {}

    func addService<T>(instance: T) {
        let key = String(T)
        serviceRegistry[key] = instance
    }

    func getService<T>(type: T.Type) -> T {
        let key = String(T)
        if let service = serviceRegistry[key] as? T {
            return service
        } else {
            fatalError("A service of \(String(T)) is not registered!")
        }
    }
}