I love Rust but its type system isn't necessarily good at modelling zero-cost abstractions. After all, one of its nicest abstractions is the iterator interface,

I love Rust but its type system isn't necessarily good at modelling zero-cost abstractions. After all, one of its nicest abstractions is the iterator interface, and that is by no means "naturally" zero-cost - you really have to trust the compiler to optimize the code back into a regular loop, and even though it's pretty good at that, it isn't perfect.