Optional `get(orSet:)` helper extension.

Example.swift

var foo: String?
var bar: String? = "bar"

print(foo) // nil
print(foo.get(orSet: "foo")) // foo
print(foo) // Optional("foo")

print(bar) // Optional("bar")
print(bar.get(orSet: "test")) // bar
print(bar) // Optional("bar")

Optional+Extensions.swift

extension Optional {
	mutating func get(orSet expression: @autoclosure () -> Wrapped) -> Wrapped {
		guard case let .some(item) = self else {
			let newItem = expression()
			self = .some(newItem)
			return newItem
		}
		
		return item
	}
}