Handy quality of life infix operator for string interpolation of optionals

Optional-String-Nil-Coalescing-Operator.swift

infix operator ???: NilCoalescingPrecedence

public func ??? <T>(optional: T?, defaultValue: @autoclosure () -> String) -> String {
    return optional.map { String(describing: $0) } ?? defaultValue()
}

Source: "Using optionals in string interpolation segments can lead to surprising or unwanted results. I defined a custom operator that lets me provide a default string value for optionals that are nil."

Usage:

var someValue: Int? = 5
print("The value is \(someValue ??? "unknown")")
// → "The value is 5"

someValue = nil
print("The value is \(someValue ??? "unknown")")
// → "The value is unknown"