That it doesn’t just wrap.
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It gives you the option when that's what you want. Why would you want that to be the default?
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But that's just rephrasing the question. Why would you define int math that way? Is it due to concern about unexpected traps escalating a system failure, like the one that destroyed the first Ariane 5?
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Well, we did talk about two reasons to change it earlier in the thread; did you read that part?
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From my perspective, regardless of how people want to handle unintended overflow, explicit intended overflow for new languages and new code in older languages can reach consensus. For signed in C it's barely even a discussion since you can't rely on it while being portable.
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If you want portable signed overflow, you *already* have to define functions for it, which can use __builtin_mul_overflow when available (add/sub is trivial anyway) and otherwise implement it by hand. GCC -fwrapv is also notably not complete and not a good idea to rely on too.
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This is probably not a viable solution to using wrapping types just due to the amount of noise it adds to your code
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It's noisy, but C doesn't support custom arithmetic types like Rust. Swift has wrapping operators. Wrapping is only commonly used for unsigned integers though. It's rarely ever wanted for signed integers, and is mostly a quirk of hardware rather than something actually used.
doc.rust-lang.org/std/num/struct is the Rust approach for something like a cryptographic cipher using modular arithmetic. It's not very normal to want it though and I don't think Rust's signed wrapping support is particularly useful, but rather it's mostly just there for completeness.
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