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You can actually implement the C++ behavior, if you want: unsafe fn super_unwrap<T>(x: Option<T>) -> T { match x { Some(val) => val,
by School-Cotton 3y ago
You can actually implement the C++ behavior, if you want:
unsafe fn super_unwrap<T>(x: Option<T>) -> T {
match x {
Some(val) => val,
None => unreachable_unchecked!(),
}
}
But defaults matter, and Rust certainly doesn’t make this kind of thing ergonomic (which is a correct decision on the Rust designers’ part).
- kaashif 3y agoYeah, absolutely. My point is that Option itself doesn't give you this API and to make an unsafe version, you have to explicitly write it. Including UB in easy to misuse places is totally unnecessary and a footgun which really does cause issues in real code.
- School-Cotton 3y agoYep, I agree completely. Just wanted to point out for completeness that rust can theoretically do the same thing as c++.
- tialaramex 3y agoYou don't have to write this, it already exists as the (unsafe of course) method Option::unwrap_unchecked Because all Rust's methods can be called as free functions, you can literally write Option::unwrap_unchecked for the same behaviour, or you can some_option.unwrap_unchecked() (in both cases you will need to be in unsafe context for this to be allowed and should write a SAFETY comment explaining why you're sure it's correct)
- School-Cotton 3y agoI see. I didn't know that method existed despite spending ~4.5 years writing Rust.
- kaashif 3y agoHa, same. I very very rarely write code in unsafe contexts which is why, I guess.