Formed in 2009, the Archive Team (not to be confused with the archive.org Archive-It Team) is a rogue archivist collective dedicated to saving copies of rapidly dying or deleted websites for the sake of history and digital heritage. The group is 100% composed of volunteers and interested parties, and has expanded into a large amount of related projects for saving online and digital history.
Added a compiler warning and explanations for irrefutable patterns. #835
Conversation
rimutaka
changed the title
|
Thanks for the PR! |
| @@ -111,6 +111,10 @@ if let (a, 3) = (1, 2) { // "(a, 3)" is refutable, and will not match | |||
| } | |||
| ``` | |||
|
|
|||
| Using an irrefutable pattern in `match`, `if let` or `while let` expressions produces a compiler warning. E.g. `if let (x, y) = (1, 2) { ... }` results in this compiler message `#[warn(irrefutable_let_patterns)]`. | |||
ehuss
Jul 7, 2020
Collaborator
In general, the reference does not cover rustc lints, so I don't think it is appropriate to add this.
In general, the reference does not cover rustc lints, so I don't think it is appropriate to add this.
| @@ -111,6 +111,10 @@ if let (a, 3) = (1, 2) { // "(a, 3)" is refutable, and will not match | |||
| } | |||
| ``` | |||
|
|
|||
| Using an irrefutable pattern in `match`, `if let` or `while let` expressions produces a compiler warning. E.g. `if let (x, y) = (1, 2) { ... }` results in this compiler message `#[warn(irrefutable_let_patterns)]`. | |||
|
|
|||
| Patterns used in `let` statements, `for` expressions, *Function* and *closure* parameters are always irrefutable. | |||
ehuss
Jul 7, 2020
Collaborator
Typically we link each phrase to the appropriate section. For example, "let statements" should link to statements.md#let-statements. There are links to all of these above, so moving those to reference-style links would probably be a good idea.
Also, I think the F in function shouldn't be capitalized.
I also might use the phrase "must be irrefutable" instead of "are always".
Typically we link each phrase to the appropriate section. For example, "let statements" should link to statements.md#let-statements. There are links to all of these above, so moving those to reference-style links would probably be a good idea.
Also, I think the F in function shouldn't be capitalized.
I also might use the phrase "must be irrefutable" instead of "are always".
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
In response to issue #799
I am very new to Rust (10 days), so it needs to be reviewed for correctness.
I got the compiler warning from running the code and the irrefutability requirements from reading: