By George!

Why to prefer Option<&T>, in one table

Some time back, I came across Logan Smith’s Choose the Right Option video, and the other day I was trying to summarize it for a colleague.

I think it boils down to this: If we assume T: ?Clone, then

to convert…	to `&Option<T>`…	to `Option<&T>`…
`x: T`	`&Some(x)` (moves `x`)	`Some(&x)`
`x: &T`	not possible	`Some(x)`
`x: Option<T>`	`&x`	`x.as_ref()`
`x: Option<Box<T>>`	not possible	`x.as_deref()`
`x: &Option<T>`	`x`	`x.as_ref()`

plus niche optimization.

Other articles

Four ways to get or insert in a Rust map

Published: Sat 07 September 2024
Updated: Sun 08 September 2024
By George Macon

In Code.

tags: rustlang

Using the entry API to insert things in more complicated situations.
read more