Suggest `Option::map_or`(_else) for `if let Some { y } else { x }`
Fixes#5203
There are two issues with this code that I have noticed:
- Use of `Option::map_or` causes it to always evaluate the code in the else block. If that block is computationally expensive or if it updates some state (such as getting the next value from an iterator), then this change would cause the code to behave differently. In either of those circumstances, it should suggest Option::map_or_else, which takes both cases as a closure and runs one. However, I don't know how to check if the expression would change some state, so I left the lint's applicability as MaybeIncorrect.
- There are lints which can trigger on specific sub-cases of this lint (`if_let_some_result`, `question_mark`, and `while_let_loop`) and suggest different changes (usually better ones because they're more specific). Is this acceptable for clippy to give multiple suggestions, or should I have the code check if those other lints trigger and then not trigger this lint if they do?
changelog: Add lint [`option_if_let_else`]
Added restriction lint: pattern-type-mismatch
changelog: Added a new restriction lint `pattern-type-mismatch`. This lint is especially helpful for beginners learning about the magic behind pattern matching. (This explanation might be worth to include in the next changelog.)
Improvements for `type_repetition_in_bounds` lint
Some improvements for `type_repetition_in_bounds`:
- add a configurable threshold to trigger the lint (#4380). The lint won't trigger anymore if there are more bounds (strictly) than `conf.max_trait_bounds` on this type.
- take generic args into account over bounded type (#4323)
- don't lint for predicates generated in macros (#4326)
Fixes#4380,
Fixes#4323,
Fixes#4326,
Closes#3764
changelog: Fix multiple FPs in `type_repetition_in_bounds` and add a configuration option
Note: the #3764 has already been fixed but not closed
Fix multiple_crate_versions error
Fix the versions of packages in the multiple_crate_versions ui test by
checking in the Cargo.lock for the test package. `ansi_term 0.11`
depends on `winapi ^0.3.4`. This means means that the expected stderr for
this test would have to be updated whenever `winapi 0.3` is updated
otherwise.
changelog: none
Fix the versions of packages in the multiple_crate_versions ui test by
checking in the Cargo.lock for the test package. `ansi_term 0.11`
depends on `winapi ^0.3.4`. This means means that the expected stderr for
this test would have to be updated whenever `winapi 0.3` is updated
otherwise.
