[jnordwick]

But it takes a lookup hit and you need an arena per object type with its memory overheard. You'll get more cache misses.

A lot of the rust performance talking points just aren't true. Rust is slower than C and C++, not by much but you can't get a true believe to even recognized this. Rust has turned into a religion.

Rust also disallows some things that you can do fine on C++ if you know our architecture because thing won't work on some machine 20 years ago (eg, it has more strict alignment requirements than any machine a consumer can see).

Throughput may only be 5% or more slower, but latency issues for rust is a much bigger issue. The devs I've talked to don't even try to pretend they have a good latency profile.