And those checks are well worth paying for, enough that Rust also has them! I'm sure Rust would have even worse ergonomics if it insisted on no runtime bounds/unwrap checks. The performance cost is low enough that every systems programming language should have spatial safety. To illustrate, Google found that hardening libc++ by adding bounds checks only led to a 0.30% performance impact on their services [1]. It's not hard to imagine that a similar run-time cost affects Zig and Rust. Both languages make attempts to optimize the checks away if the operation is known-safe. Although, maybe Rust is more successful due to the borrow checker.
> and/or misusable allocator passing.
Could you clarify how allocator misuse might lead to a spatial safety violation?
[1] https://security.googleblog.com/2024/11/retrofitting-spatial...