Re: New conditional assignment facility

[N. Thiebaud]

> I'm pretty uncomfortable with this inversion of expectation,

Indeed.
This inversion sounds confusing and that use case is already possible,
just not with a 'shortcut' notation.

> Or maybe we should say the "?+=" operator isn't supported and give an
> error since it has no function

that also leave open the future use of that notation, if usage and
experience point to a 'better' solution

If it not an error, there won't be any practical way to change that
decision in the future