Comment by ninkendo
3 hours ago
Box<T> used to be ~T early on in rust… (then it became a `box` keyword, before being removed entirely.) They got rid of it because they wanted to move more things into libraries and have a less opinionated compiler.
I think I agree though, especially with Option. Swift’s option syntax (and kotlin’s which is similar) is so much better, a simple question mark in the type. Options are important enough that dedicated syntax makes so much sense. Rust blew their chance here with ? meaning “maybe early return”, it would have been a lot more useful as an Option indicator.
I used to think this too, but nowadays I think this would have been a mistake. Result is actually the more important and fundamental type, not Option, and giving Option special syntax would cause people to want to favor it over Result even when it shouldn't be. If anything, I think that `?` should have been reserved as a suffix for function names (not types) that return Result, so that instead of `fn try_foo()` and `let x = try_foo();` we could have `fn foo?()` and `let x = foo?();`, and then the current `?` operator could just be spelled `.try`, akin to `.await`. (And then we maybe could go further and reserve `!` as a suffix for functions that can panic...)
The Try trait (representing the ? the operation) is super cool though! I wish it was marked stable so you could implement it for types without using the nightly compiler.
Note that both Option and Result implement that same trait.
Perhaps if try blocks ever become a thing... we can finally use it for our own types ;)
https://doc.rust-lang.org/std/ops/trait.Try.html