[swift-evolution] Optional Assignment Operator

[Joe Groff]

> On Jan 25, 2017, at 9:47 AM, Jacob Bandes-Storch <jtbandes at gmail.com> wrote:
> 
> Really? My observation from a quick test is that "a? = b" assigns b to a if a already has a value, or does nothing if it's nil. This is sort of the opposite of what's being proposed, which is that "a ?= b" should assign to a only if it does NOT have a value.


My mistake, I misread the proposal. What Nichi appears to be suggesting is an assignment that only happens when `b` has a value. I would hesitate to spell that `?=` since that's so similar to '? =', but perhaps it's useful, though there are many ways to spell that already.

-Joe