Set a dictionary key using an optional. If the optional exists, the key will be set, if the optional is nil, the key will not be set.

import ConditionalSet

var dict: [String: String] = [:]

var maybeString: String? = nil

dict.set("win", maybeString)
// => [:]

// now make maybeString not nil
maybeString = "win!"

dict.set("win", maybeString)
// => ["win" : "win!"]

Add Later to your Package.swift file:

import PackageDescription

let package = Package(
    name: "YourPackageName",
    dependencies: [
        .Package(url: "https://github.com/coryalder/ConditionalSet.git", majorVersion: 0),
    ]
)