> it needs to have an unsafe, turn-off-all-checks-run as fast as you can mode
This will never happen, as it is contrary to the goals of the project. As mentioned by others, locally, you can ignore some checks, but there won't be a compiler flag to turn them off.
In some ways, it's too early to talk about it, and in some ways, it's not. It's not too early to talk about decisions which would place a certain upper bound on performance, but it's kinda too early to do some kinds of direct comparisons. The team has not really been working on performance generally, as the focus is to get the language semantics correctly. There's lots of places, for example, where rustc generates subpar LLVM IR, and it's a matter of someone writing a patch.
This will never happen, as it is contrary to the goals of the project. As mentioned by others, locally, you can ignore some checks, but there won't be a compiler flag to turn them off.
In some ways, it's too early to talk about it, and in some ways, it's not. It's not too early to talk about decisions which would place a certain upper bound on performance, but it's kinda too early to do some kinds of direct comparisons. The team has not really been working on performance generally, as the focus is to get the language semantics correctly. There's lots of places, for example, where rustc generates subpar LLVM IR, and it's a matter of someone writing a patch.