133 lines
2.8 KiB
Rust
133 lines
2.8 KiB
Rust
#![warn(clippy::while_let_loop, clippy::empty_loop, clippy::while_let_on_iterator)]
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#![allow(dead_code, clippy::never_loop, unused, clippy::cognitive_complexity)]
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fn main() {
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let mut iter = 1..20;
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while let Option::Some(x) = iter.next() {
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println!("{}", x);
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}
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let mut iter = 1..20;
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while let Some(x) = iter.next() {
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println!("{}", x);
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}
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let mut iter = 1..20;
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while let Some(_) = iter.next() {}
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let mut iter = 1..20;
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while let None = iter.next() {} // this is fine (if nonsensical)
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let mut iter = 1..20;
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if let Some(x) = iter.next() {
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// also fine
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println!("{}", x)
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}
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// the following shouldn't warn because it can't be written with a for loop
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let mut iter = 1u32..20;
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while let Some(x) = iter.next() {
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println!("next: {:?}", iter.next())
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}
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// neither can this
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let mut iter = 1u32..20;
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while let Some(x) = iter.next() {
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println!("next: {:?}", iter.next());
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}
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// or this
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let mut iter = 1u32..20;
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while let Some(x) = iter.next() {
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break;
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}
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println!("Remaining iter {:?}", iter);
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// or this
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let mut iter = 1u32..20;
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while let Some(x) = iter.next() {
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iter = 1..20;
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}
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}
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// Issue #1188
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fn refutable() {
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let a = [42, 1337];
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let mut b = a.iter();
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// consume all the 42s
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while let Some(&42) = b.next() {}
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let a = [(1, 2, 3)];
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let mut b = a.iter();
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while let Some(&(1, 2, 3)) = b.next() {}
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let a = [Some(42)];
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let mut b = a.iter();
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while let Some(&None) = b.next() {}
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/* This gives “refutable pattern in `for` loop binding: `&_` not covered”
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for &42 in b {}
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for &(1, 2, 3) in b {}
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for &Option::None in b.next() {}
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// */
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}
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fn nested_loops() {
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let a = [42, 1337];
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let mut y = a.iter();
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loop {
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// x is reused, so don't lint here
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while let Some(v) = y.next() {}
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}
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let mut y = a.iter();
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for _ in 0..2 {
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while let Some(v) = y.next() {
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// y is reused, don't lint
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}
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}
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loop {
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let mut y = a.iter();
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while let Some(v) = y.next() {
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// use a for loop here
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}
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}
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}
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fn issue1121() {
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use std::collections::HashSet;
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let mut values = HashSet::new();
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values.insert(1);
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while let Some(&value) = values.iter().next() {
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values.remove(&value);
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}
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}
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fn issue2965() {
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// This should not cause an ICE and suggest:
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//
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// for _ in values.iter() {}
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//
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use std::collections::HashSet;
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let mut values = HashSet::new();
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values.insert(1);
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while let Some(..) = values.iter().next() {
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values.remove(&1);
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}
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}
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fn issue3670() {
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let array = [Some(0), None, Some(1)];
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let mut iter = array.iter();
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while let Some(elem) = iter.next() {
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let _ = elem.or_else(|| *iter.next()?);
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}
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}
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