Using optionals easily: save you from frequent coelsing

SafeOptional.swift

//
//  SafeOptional.swift
//  TodoMVVM
//
//  Created by Ashik uddin Ahmad on 7/20/17.
//  Copyright © 2017 Ashik uddin Ahmad. All rights reserved.
//

import Foundation

protocol SafeUnwrappable { static func nilValue()->Self }

extension Optional where Wrapped:SafeUnwrappable {
    var safe: Wrapped {
        switch self {
        case .some(let value): return value
        case .none: return Wrapped.nilValue()
        }
    }
}

extension Int:SafeUnwrappable {
    static func nilValue() -> Int { return 0 }
}
extension Float:SafeUnwrappable {
    static func nilValue() -> Float { return 0 }
}
extension Double:SafeUnwrappable {
    static func nilValue() -> Double { return 0 }
}
extension String: SafeUnwrappable {
    static func nilValue() -> String { return "" }
}
extension Array: SafeUnwrappable {
    static func nilValue() -> Array<Element> { return [] }
}
extension Dictionary: SafeUnwrappable {
    static func nilValue() -> Dictionary<Key, Value> { return [:] }
}