mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-12-05 02:50:32 +00:00
d0c1f8ada2
- fix `is_refutable` for slice patterns - fix `is_refutable` for bindings - add some TODO-s for cases, which can not be fixed easily
218 lines
4.5 KiB
Rust
218 lines
4.5 KiB
Rust
// run-rustfix
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#![warn(clippy::while_let_on_iterator)]
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#![allow(clippy::never_loop, unreachable_code, unused_mut)]
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#![feature(or_patterns)]
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fn base() {
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let mut iter = 1..20;
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for x in iter {
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println!("{}", x);
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}
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let mut iter = 1..20;
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for x in iter {
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println!("{}", x);
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}
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let mut iter = 1..20;
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for _ in iter {}
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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(_) = 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(_) = 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(_) = 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(_) = 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 refutable2() {
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// Issue 3780
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{
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let v = vec![1, 2, 3];
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let mut it = v.windows(2);
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while let Some([x, y]) = it.next() {
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println!("x: {}", x);
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println!("y: {}", y);
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}
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let mut it = v.windows(2);
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while let Some([x, ..]) = it.next() {
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println!("x: {}", x);
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}
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let mut it = v.windows(2);
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while let Some([.., y]) = it.next() {
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println!("y: {}", y);
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}
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let mut it = v.windows(2);
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for [..] in it {}
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let v = vec![[1], [2], [3]];
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let mut it = v.iter();
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while let Some([1]) = it.next() {}
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let mut it = v.iter();
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for [_x] in it {}
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}
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// binding
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{
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let v = vec![1, 2, 3];
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let mut it = v.iter();
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while let Some(x @ 1) = it.next() {
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println!("{}", x);
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}
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let v = vec![[1], [2], [3]];
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let mut it = v.iter();
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for x @ [_] in it {
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println!("{:?}", x);
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}
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}
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// false negative
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{
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let v = vec![1, 2, 3];
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let mut it = v.iter().map(Some);
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while let Some(Some(_) | None) = it.next() {
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println!("1");
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}
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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(_) = 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(_) = 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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for _ in y {
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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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}
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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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fn issue1654() {
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// should not lint if the iterator is generated on every iteration
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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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while let Some(..) = values.iter().map(|x| x + 1).next() {}
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let chars = "Hello, World!".char_indices();
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while let Some((i, ch)) = chars.clone().next() {
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println!("{}: {}", i, ch);
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}
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}
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fn main() {
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base();
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refutable();
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refutable2();
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nested_loops();
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issue1121();
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issue2965();
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issue3670();
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issue1654();
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}
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