Skip to content

Improve docs for option_option #5403

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Apr 2, 2020
Merged

Improve docs for option_option #5403

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
db3423f
Improve docs for option_option
farnz Apr 2, 2020
f3f1bab
Update types.rs
farnz Apr 2, 2020
50ecc12
Update types.rs
farnz Apr 2, 2020
5f8b696
Update clippy_lints/src/types.rs
farnz Apr 2, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 18 additions & 1 deletion clippy_lints/src/types.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -99,14 +99,31 @@ declare_clippy_lint! {
/// represents an optional optional value which is logically the same thing as an optional
/// value but has an unneeded extra level of wrapping.
///
/// If you have a case where `Some(Some(_))`, `Some(None)` and `None` are distinct cases,
/// consider a custom `enum` instead, with clear names for each case.
///
/// **Known problems:** None.
///
/// **Example**
/// ```rust
/// fn x() -> Option<Option<u32>> {
/// fn get_data() -> Option<Option<u32>> {
/// None
/// }
/// ```
///
/// Better:
///
/// ```rust
/// pub enum Contents {
/// Data(Vec<u8>), // Was Some(Some(Vec<u8>))
/// NotYetFetched, // Was Some(None)
/// None, // Was None
/// }
///
/// fn get_data() -> Contents {
/// Contents::None
/// }
/// ```
pub OPTION_OPTION,
pedantic,
"usage of `Option<Option<T>>`"
Expand Down