Exactly. In the announcement (https://groups.google.com/forum/#!topic/puffslang/2z61mNTAMns/discussion https://groups.google.com/forum/#!topic/puffslang/2z61mNT

Exactly. In the announcement (https://groups.google.com/forum/#!topic/puffslang/2z61mNTAMns/discussion https://groups.google.com/forum/#!topic/puffslang/2z61mNTAMn...), I said "Rust can check for arithmetic overflow (at run time), but after some debate, the Rust team decided to disable such checks when building in release mode, for performance reasons. Obviously, though, we don't ship our users debug builds." Puffs enforces arithmetic overflow checks (it's not optional, and you don't have to specify that you intend to check overflow). It differs from Rust in that it's done entirely at compile time instead of at run time.