Realistically you don't unless you really really need it. If you really need it you drop to unsafe and build a "safe" interface in-front of it. Rust makes writ

Realistically you don't unless you really really need it. If you really need it you drop to unsafe and build a "safe" interface in-front of it. Rust makes writing very high performance multi-threaded code incredibly hard because most of the tricks to get that last bit of performance out are basically asking to generated races and are near impossible to express in a way that is provably safe. You basically thinking of your data-layout from day one if you need that kind of performance your just going to have to deal with a bunch of unsafe in your codebase.