What, if anything, is a multi thread equiv of Box ?
What would the semantics be? For
Arc, the difference is whether the multiple bindings sharing ownership to the same data can live on different threads. But
Box owns its data exclusively, so there's nothing to be thread-unsafe here.
My answer would just be
With unstable allocator API
Box<T, SomeUnsyncThreadLocalAllocator> can be considered as single threaded box.