Does Swift have a null coalescing operator and if not, what is an example of a custom operator?

Question

A common feature in many languages, the Null Coalescing Operator, is a binary operator often used to shorten expressions of the type:

x = possiblyNullValue N         


        

Answer 1

I blogged about a custom operator function that provides nil-coalescing here: http://ijoshsmith.com/2014/07/24/nil-coalescing-operator-in-swift/

My choice of operator was !! which combines the logical not operator (!) and the unwrap operator (!) for a "if cannot unwrap" semantic. Seems I was late to the party, given this thread is already over a month old. Either way, here's my implementation in case you're interested...

operator infix !! {}

@infix func !!  (
    value: T?,
    defaultValue: @auto_closure () -> T)
    -> T
{
    return value ? value! : defaultValue()
}