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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /src/tools/clippy/tests/ui/infinite_iter.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/tools/clippy/tests/ui/infinite_iter.rs')
-rw-r--r--src/tools/clippy/tests/ui/infinite_iter.rs68
1 files changed, 68 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/infinite_iter.rs b/src/tools/clippy/tests/ui/infinite_iter.rs
new file mode 100644
index 000000000..a1e5fad0c
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+++ b/src/tools/clippy/tests/ui/infinite_iter.rs
@@ -0,0 +1,68 @@
+use std::iter::repeat;
+fn square_is_lower_64(x: &u32) -> bool {
+ x * x < 64
+}
+
+#[allow(clippy::maybe_infinite_iter)]
+#[deny(clippy::infinite_iter)]
+fn infinite_iters() {
+ repeat(0_u8).collect::<Vec<_>>(); // infinite iter
+ (0..8_u32).take_while(square_is_lower_64).cycle().count(); // infinite iter
+ (0..8_u64).chain(0..).max(); // infinite iter
+ (0_usize..)
+ .chain([0usize, 1, 2].iter().cloned())
+ .skip_while(|x| *x != 42)
+ .min(); // infinite iter
+ (0..8_u32)
+ .rev()
+ .cycle()
+ .map(|x| x + 1_u32)
+ .for_each(|x| println!("{}", x)); // infinite iter
+ (0..3_u32).flat_map(|x| x..).sum::<u32>(); // infinite iter
+ (0_usize..).flat_map(|x| 0..x).product::<usize>(); // infinite iter
+ (0_u64..).filter(|x| x % 2 == 0).last(); // infinite iter
+ (0..42_u64).by_ref().last(); // not an infinite, because ranges are double-ended
+ (0..).next(); // iterator is not exhausted
+}
+
+#[deny(clippy::maybe_infinite_iter)]
+fn potential_infinite_iters() {
+ (0..).zip((0..).take_while(square_is_lower_64)).count(); // maybe infinite iter
+ repeat(42).take_while(|x| *x == 42).chain(0..42).max(); // maybe infinite iter
+ (1..)
+ .scan(0, |state, x| {
+ *state += x;
+ Some(*state)
+ })
+ .min(); // maybe infinite iter
+ (0..).find(|x| *x == 24); // maybe infinite iter
+ (0..).position(|x| x == 24); // maybe infinite iter
+ (0..).any(|x| x == 24); // maybe infinite iter
+ (0..).all(|x| x == 24); // maybe infinite iter
+
+ (0..).zip(0..42).take_while(|&(x, _)| x != 42).count(); // not infinite
+ repeat(42).take_while(|x| *x == 42).next(); // iterator is not exhausted
+}
+
+fn main() {
+ infinite_iters();
+ potential_infinite_iters();
+}
+
+mod finite_collect {
+ use std::collections::HashSet;
+
+ struct C;
+ impl FromIterator<i32> for C {
+ fn from_iter<I: IntoIterator<Item = i32>>(iter: I) -> Self {
+ C
+ }
+ }
+
+ fn check_collect() {
+ let _: HashSet<i32> = (0..).collect(); // Infinite iter
+
+ // Some data structures don't collect infinitely, such as `ArrayVec`
+ let _: C = (0..).collect();
+ }
+}