In Zig we embrace undefined behavior. It's what allows tools to catch mistakes, and it's what arms the optimizer with the assumptions it needs to be effective.

In Zig we embrace undefined behavior. It's what allows tools to catch mistakes, and it's what arms the optimizer with the assumptions it needs to be effective. For example, not only is it undefined behavior to overflow on signed integer addition, in Zig it's also undefined behavior to overflow on unsigned integer addition. If you want wrapping integer addition, you have to use the wrapping integer addition operator, which is defined to wraparound on overflow. Here's the trick though - Zig catches most kinds of undefined behavior before they have a chance to cause problems in release builds. Some undefined behavior is caught at compile time, and otherwise most undefined behavior is caught at runtime, in debug builds. And finally, if you are not confident in the level of testing your software has undergone, you can make a "release-safe" build, which has optimizations on, but includes undefined behavior checks and will crash (or invoke user-defined panic function) rather than invoke undefined behavior. You can see some examples of this here: https://ziglang.org/documentation/master/#Undefined-Behavior https://ziglang.org/documentation/master/#Undefined-Behavior