A roadmap for improving Swift performance predictability: ARC improvements and ownership control

[timdecode (Timothy Davison)]

@Joe_Groff

There are other places where inout bindings for in-place mutation are desirable, but aren’t currently available, and we can extend inout bindings to be available in those places as well. For instance, when switch -ing an enum , we would like to be able to bind to its payload, and update it in place:

This will be a huge win for us.

With read and modify accessors, and inout, will mutating for-loops be possible on MutableCollectionss?

for &particle in particles {
   particle.position = integrate(particle)
}

I do a lot of realtime simulation and I am frequently surprised at the amount of ARC traffic when I profile our code in Instruments (it's possible to eliminate much of it, but not always). These performance improvements are very welcome and it should be possible to write predictably performant code at the first implementation. Wonderful.