Working With Rust Result - Summary

If you’ve made it this far, you’re probably overwhelmed by all the different methods and their uses! It helps to try and learn to use them one at a time; as and when needed. The following table summarises which method you would use under different circumstances.

What do you want to do?	Method to use
Create a `Result`	Constructor: `Ok(value)` Constructor: `Err(value)`
Get both values out of a `Result`	`Patten matching` `map_or_else` `map_or` `unwrap` panics `unwrap_or` `unwrap_or_else` `unwrap_or_default` `expect` panics
Run a function on the value inside `Ok`	`map` `and_then`
Run a function on the value inside `Err`	`or_else` `map_err`
Get the value inside `Ok`	`unwrap` panics `expect` panics `? operator`
Get the value inside `Ok` with fallback	`Patten matching` `map_or` `unwrap_or` `unwrap_or_else` `unwrap_or_default`
Get the value inside `Err`	`unwrap_err` panics `expect_err` panics
Get the value inside `Err` with fallback	`Patten matching` `map_or` `unwrap_or` `unwrap_or_else` `unwrap_or_default`
Combine two `Result`s that are `Ok`	`and_then` `and` `? operator`
Combine two `Result`s that are `Err`	`or` `or_else`
Convert `Ok` to `Option` as `Some`	`ok`
Convert `Err` to `Option` as `Some`	`err`
Convert `Result<Option>` to `Option<Result>`	`transpose`
Test for `Ok`	`is_ok`
Test for `Err`	`is_err`
Test for `Ok` and run a predicate	`is_ok_and`
Test for `Err` and run a predicate	`is_err_and`

I hope this somewhat lengthy series helped you learn some more about Rust’s Result type. If you found any errors or omissions or found this useful, please leave a comment.

Feedback from the review lounge

SirKastic23

A huge thanks to SirKastic23 for giving me some sound feedback on Reddit:

Comment
byu/ssanjs from discussion
inrust

I’ve made the updates to the sections marked “unsafe”. I’ll get to dark mode in the near future.

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