50 lines
988 B
Rust
50 lines
988 B
Rust
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#![warn(let_unit_value)]
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#![allow(unused_variables)]
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macro_rules! let_and_return {
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($n:expr) => {{
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let ret = $n;
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}}
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}
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fn main() {
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let _x = println!("x");
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let _y = 1; // this is fine
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let _z = ((), 1); // this as well
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if true {
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let _a = ();
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}
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consume_units_with_for_loop(); // should be fine as well
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let_and_return!(()) // should be fine
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}
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// Related to issue #1964
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fn consume_units_with_for_loop() {
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// `for_let_unit` lint should not be triggered by consuming them using for loop.
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let v = vec![(), (), ()];
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let mut count = 0;
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for _ in v {
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count += 1;
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}
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assert_eq!(count, 3);
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// Same for consuming from some other Iterator<Item = ()>.
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let (tx, rx) = ::std::sync::mpsc::channel();
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tx.send(()).unwrap();
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drop(tx);
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count = 0;
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for _ in rx.iter() {
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count += 1;
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}
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assert_eq!(count, 1);
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}
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#[derive(Copy, Clone)]
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pub struct ContainsUnit(()); // should be fine
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