Many (maybe most) languages are OK with changing behaviour/code between debug and release builds, e.g. disabling `assert`s and even the optimisations themselves

Many (maybe most) languages are OK with changing behaviour/code between debug and release builds, e.g. disabling `assert`s and even the optimisations themselves. Of course, this is suboptimal in some cases, and thus providing a way to disable it is good and thus rustc has -C debug-assertions=on, and a currently-unstable flag to control just the overflow checks themselves. Seguing from that first flag, Rust makes it explicit when an assertion is OK to omit by providing both debug_assert! (removed in release) and assert! (never removed), so I guess Rust is in a middle ground that's the reverse of the middle ground of a language like, say, Swift, which removes assertions but not overflow checks in its default optimised build.