Re:Rust should not have provided `unwrap`
by kannanvijayan on Friday July 15, 2022 @01:36PM
(#32110744)
Not necessarily, you can extract the inner type by using the match as an expression, e.g.:
```
let val = match res {
Err(e) => {
...
return ...;
}
Ok(v) => v,
};
// Use val without unwrapping here.
```
That said, even though I'd avoid unwrap in this particular case in my code, I generally disagree with the author.
Taking out unwrap and leaving in expect would simply lead to a bunch of code that goes `let val = result.expect("!");`, which is equivalently bad when held up against the criticisms the author makes of unwrap.
Unwrap isn't really harmful so much as a symptom and an escape valve around the fact that our type systems really aren't powerful enough to derive all the invariants the programmer can about their code.
``` let val = match res { Err(e) => { ... return ...; } Ok(v) => v, }; // Use val without unwrapping here. ```
That said, even though I'd avoid unwrap in this particular case in my code, I generally disagree with the author.
Taking out unwrap and leaving in expect would simply lead to a bunch of code that goes `let val = result.expect("!");`, which is equivalently bad when held up against the criticisms the author makes of unwrap.
Unwrap isn't really harmful so much as a symptom and an escape valve around the fact that our type systems really aren't powerful enough to derive all the invariants the programmer can about their code.