{flat_,}map_identity: recognize |[x, y]| [x, y] as an identity function as well
#15229
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{flat_,}map_identity: recognize |[x, y]| [x,y] as identity function as well{flat_,}map_identity: recognize |[x, y]| [x, y] as an identity function as well
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should I add struct destructuring as well? It would be completely irrelevant EDIT: on another thought... maybe not -- even the "simpler" thing, tuple structs, would require delving into the horrors of |
y21
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This looks good to me, thanks! Nice that you thought of match ergonomics, in the past they've caused some trouble in these identity lints :)
As for struct destructuring, I suppose conceptually it could make sense for this lint to catch them, but yeah, definitely not something you need to do here, this is a solid improvement on its own.
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Could you squash the commits? |
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#15261) Follow-up of #15229, as described in #15229 (comment) -- it turned out to be not that difficult after all! changelog: [`map_identity`,`flat_map_identity`]: also recognize (tuple) struct de- and resctructuring r? @y21
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…15268) While working on #15229, I noticed a test case in `map_identity` which avoids linting in the case where removing the `.map()` would require the iterator variable to be made mutable. But then I saw #14140, and thought I'd try to adapt its approach, by suggesting both removing the `.map()` _and_ making the variable mutable. This is WIP only because I'm not sure about the very last `diag.span_note` -- I think having a method chained immediately after the `.map()` is the only case which requires adding `mut`, so it should be safe to say that `method_requiring_mut` is always `Some`. I'd like to do a lintcheck run to see if that's actually true. @samueltardieu do you think this is a good approach? Maybe there are more lints where we could lint + suggest making the variable mut, instead of not linting? changelog:`map_identity`: suggest making the variable mutable when necessary
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changelog: [
map_identity,flat_map_identity]: also recognize|[x, y]| [x, y]fixes #15198