Optimize Rust Code

Make a measured Rust hot path cheaper without changing observable behavior. Each change applies one reference card to a cost that a profile attributes, is proven equivalent by an oracle, and is kept only if the metric the card names improves: allocation calls, inner I/O calls, hash computations, an instruction pattern in the assembly, or a Criterion interval. The cards state when a construct is wrong and what it breaks, so read the card before applying a construct.

Workflow