It does seem to me moving in that direction - not at the type level but at the member level. Property wrappers already allow some interesting possibilities wit

It does seem to me moving in that direction - not at the type level but at the member level. Property wrappers already allow some interesting possibilities with customizing the storage and usage of particular member variables, and there was a thread today about exposing the memory locations of reference type members, which would unlock a lot of optimization opportunities: https://forums.swift.org/t/pitch-exposing-the-memory-locations-of-class-instance-variables/30584 https://forums.swift.org/t/pitch-exposing-the-memory-locatio... I'm not sure whether swift can ever really get there with respect to performance, given the foundational decisions regarding ARC and copy-on-write. But I would love a language with Swift's type system and sensibilities and a bit more control over how memory is handled.