You can tell the compiler that you want your crate to perform the checks regardless.

https://doc.rust-lang.org/cargo/reference/profiles.html#over...

You can also either (in nightly Rust) use the strict APIs which make it explicit that you want the overflow panics, or, (stably) use the checked APIs and then do whatever makes sense, which could include explicitly panic when overflow would happen unexpectedly.

This would let you have e.g. code where most arithmetic is checked, but a tight inner loop you're pretty sure won't overflow only has checks in debug (in release it will wrap, but you should not rely on that for correctness, unintended overflow is a bug)