generators: redundant_pattern_matching triggers on yield #10451
Description
Summary
.
Lint Name
redundant_pattern_matching
Reproducer
I tried this code:
#![feature(generator_trait)] #![feature(generators)] #![deny(unused_braces, unused_parens)] use std::ops::Generator; use std::pin::Pin; fn main() { let mut x = |_| { while let Some(_) = (yield) {} }; let _ = Pin::new(&mut x).resume(Some(5)); }I saw this happen:
warning: redundant pattern matching, consider using `is_some()` --> issue-74883-unused-paren-baren-yield.rs:10:19 | 10 | while let Some(_) = (yield) {} | ----------^^^^^^^---------- help: try this: `while (yield).is_some()` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pattern_matching Using the suggested yield.is_some() introduces a type error:
error[E0282]: type annotations needed --> issue-74883-unused-paren-baren-yield.rs:9:18 | 9 | let mut x = |_| { | ^ 10 | while (yield).is_some() {} | ------- type must be known at this point | help: consider giving this closure parameter an explicit type | 9 | let mut x = |_: /* Type */| { | ++++++++++++ warning: unused import: `std::ops::Generator` --> issue-74883-unused-paren-baren-yield.rs:5:5 | 5 | use std::ops::Generator; | ^^^^^^^^^^^^^^^^^^^ | = note: `#[warn(unused_imports)]` on by default Version
rustc 1.69.0-nightly (44cfafe2f 2023-03-03) binary: rustc commit-hash: 44cfafe2fafe816395d3acc434663a45d5178c41 commit-date: 2023-03-03 host: x86_64-unknown-linux-gnu release: 1.69.0-nightly LLVM version: 15.0.7 Additional Labels
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