add a lint [unused_any_all]: the return values of Iterator::{any,all} are not used.

CHANGELOG.md

@@ -5995,6 +5995,7 @@ Released 2018-09-13
 [`unsound_collection_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsound_collection_transmute
 [`unstable_as_mut_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_mut_slice
 [`unstable_as_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_slice
+[`unused_any_all`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_any_all
 [`unused_async`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_async
 [`unused_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_collect
 [`unused_enumerate_index`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_enumerate_index

clippy_lints/src/declared_lints.rs

@@ -738,6 +738,7 @@ pub static LINTS: &[&crate::LintInfo] = &[
     crate::unnecessary_wraps::UNNECESSARY_WRAPS_INFO,
     crate::unnested_or_patterns::UNNESTED_OR_PATTERNS_INFO,
     crate::unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME_INFO,
+    crate::unused_any_all::UNUSED_ANY_ALL_INFO,
     crate::unused_async::UNUSED_ASYNC_INFO,
     crate::unused_io_amount::UNUSED_IO_AMOUNT_INFO,
     crate::unused_peekable::UNUSED_PEEKABLE_INFO,

clippy_lints/src/lib.rs

@@ -367,6 +367,7 @@ mod unnecessary_struct_initialization;
 mod unnecessary_wraps;
 mod unnested_or_patterns;
 mod unsafe_removed_from_name;
+mod unused_any_all;
 mod unused_async;
 mod unused_io_amount;
 mod unused_peekable;
@@ -799,6 +800,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
     store.register_late_pass(move |_| Box::new(if_then_some_else_none::IfThenSomeElseNone::new(conf)));
     store.register_late_pass(|_| Box::new(bool_assert_comparison::BoolAssertComparison));
     store.register_early_pass(move || Box::new(module_style::ModStyle));
+    store.register_late_pass(|_| Box::<unused_any_all::UnusedAnyAll>::default());
     store.register_late_pass(|_| Box::<unused_async::UnusedAsync>::default());
     store.register_late_pass(move |tcx| Box::new(disallowed_types::DisallowedTypes::new(tcx, conf)));
     store.register_late_pass(move |tcx| Box::new(missing_enforced_import_rename::ImportRename::new(tcx, conf)));

clippy_lints/src/unused_any_all.rs

@@ -0,0 +1,95 @@
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::macros::HirNode;
+use rustc_hir::{Expr, ExprKind, QPath, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::impl_lint_pass;
+use rustc_span::sym;
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for calls to `any` or `all` where the return values are ignored.
+    ///
+    /// Ignoring the return value of `any` or `all` is suspicious and may indicate a mistake.
+    /// The returned value is usually intended to be used as a condition.
+    /// If `any` or `all` is called solely for their side effects on the iterator or their `FnMut` argument,
+    /// it's generally better to consume the iterator using a plain `for` loop.
+    ///
+    /// ### Example
+    /// ```no_run
+    /// let mut days_without_accident = 0;
+    /// (0..).all(|day| {
+    ///     if day % 5 == 0 {
+    ///         return false
+    ///     }
+    ///
+    ///     days_without_accident += 1;
+    ///     true
+    /// });
+    /// ```
+
+    #[clippy::version = "1.82.0"]
+    pub UNUSED_ANY_ALL,
+    suspicious,
+    "unused result of `Iterator::any` or `Iterator::all`"
+}
+
+#[derive(Default)]
+pub struct UnusedAnyAll;
+
+impl_lint_pass!(UnusedAnyAll => [UNUSED_ANY_ALL]);
+
+impl<'tcx> LateLintPass<'tcx> for UnusedAnyAll {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+        let sym_any = sym::any;
+        let sym_all = sym::all;
+        let sym_iter = sym::Iterator;
+
+        let ExprKind::Block(block, _label) = &expr.kind else {
+            return;
+        };
+
+        for statement in block.stmts {
+            let StmtKind::Semi(semi) = statement.kind else { continue };
+
+            let method_name = match &semi.kind {
+                ExprKind::MethodCall(path, expr, _args, _span)
+                    if path.ident.name == sym_any
+                        || path.ident.name == sym_all && clippy_utils::is_trait_method(cx, expr, sym::Iterator) =>
+                {
+                    path.ident.name
+                },
+                ExprKind::Call(path, _args) => match path.kind {
+                    ExprKind::Path(QPath::Resolved(_, path))
+                        if path
+                            .segments
+                            .first()
+                            .map(|s| s.ident.name)
+                            .zip(path.segments.last().map(|s| s.ident.name))
+                            == Some((sym_iter, sym_all)) =>
+                    {
+                        sym_all
+                    },
+                    ExprKind::Path(QPath::Resolved(_, path))
+                        if path
+                            .segments
+                            .first()
+                            .map(|s| s.ident.name)
+                            .zip(path.segments.last().map(|s| s.ident.name))
+                            == Some((sym_iter, sym_any)) =>
+                    {
+                        sym_any
+                    },
+                    _ => continue,
+                },
+                _ => continue,
+            };
+
+            span_lint(
+                cx,
+                UNUSED_ANY_ALL,
+                semi.span(),
+                format!("unused result of `Iterator::{method_name}`"),
+            );
+        }
+    }
+}

tests/ui/infinite_iter.rs

@@ -1,4 +1,4 @@
-#![allow(clippy::uninlined_format_args)]
+#![allow(clippy::uninlined_format_args, clippy::unused_any_all)]
 
 use std::iter::repeat;
 fn square_is_lower_64(x: &u32) -> bool {

tests/ui/needless_character_iteration.fixed

@@ -1,5 +1,5 @@
 #![warn(clippy::needless_character_iteration)]
-#![allow(clippy::map_identity, clippy::unnecessary_operation)]
+#![allow(clippy::map_identity, clippy::unnecessary_operation, clippy::unused_any_all)]
 
 #[derive(Default)]
 struct S {

tests/ui/needless_character_iteration.rs

@@ -1,5 +1,5 @@
 #![warn(clippy::needless_character_iteration)]
-#![allow(clippy::map_identity, clippy::unnecessary_operation)]
+#![allow(clippy::map_identity, clippy::unnecessary_operation, clippy::unused_any_all)]
 
 #[derive(Default)]
 struct S {

tests/ui/needless_collect.fixed

@@ -1,4 +1,10 @@
-#![allow(unused, clippy::needless_if, clippy::suspicious_map, clippy::iter_count)]
+#![allow(
+    unused,
+    clippy::needless_if,
+    clippy::suspicious_map,
+    clippy::iter_count,
+    clippy::unused_any_all
+)]
 
 use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList};
 

tests/ui/needless_collect.rs

@@ -1,4 +1,10 @@
-#![allow(unused, clippy::needless_if, clippy::suspicious_map, clippy::iter_count)]
+#![allow(
+    unused,
+    clippy::needless_if,
+    clippy::suspicious_map,
+    clippy::iter_count,
+    clippy::unused_any_all
+)]
 
 use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, LinkedList};
 

tests/ui/needless_collect.stderr

@@ -1,5 +1,5 @@
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:9:29
+  --> tests/ui/needless_collect.rs:15:29
    |
 LL |     let len = sample.iter().collect::<Vec<_>>().len();
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()`
@@ -8,109 +8,109 @@ LL |     let len = sample.iter().collect::<Vec<_>>().len();
    = help: to override `-D warnings` add `#[allow(clippy::needless_collect)]`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:10:22
+  --> tests/ui/needless_collect.rs:16:22
    |
 LL |     if sample.iter().collect::<Vec<_>>().is_empty() {
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:13:28
+  --> tests/ui/needless_collect.rs:19:28
    |
 LL |     sample.iter().cloned().collect::<Vec<_>>().contains(&1);
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `any(|x| x == 1)`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:18:35
+  --> tests/ui/needless_collect.rs:24:35
    |
 LL |     sample.iter().map(|x| (x, x)).collect::<HashMap<_, _>>().is_empty();
    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:19:35
+  --> tests/ui/needless_collect.rs:25:35
    |
 LL |     sample.iter().map(|x| (x, x)).collect::<BTreeMap<_, _>>().is_empty();
    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:26:19
+  --> tests/ui/needless_collect.rs:32:19
    |
 LL |     sample.iter().collect::<LinkedList<_>>().len();
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:27:19
+  --> tests/ui/needless_collect.rs:33:19
    |
 LL |     sample.iter().collect::<LinkedList<_>>().is_empty();
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:28:28
+  --> tests/ui/needless_collect.rs:34:28
    |
 LL |     sample.iter().cloned().collect::<LinkedList<_>>().contains(&1);
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `any(|x| x == 1)`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:29:19
+  --> tests/ui/needless_collect.rs:35:19
    |
 LL |     sample.iter().collect::<LinkedList<_>>().contains(&&1);
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `any(|x| x == &1)`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:32:19
+  --> tests/ui/needless_collect.rs:38:19
    |
 LL |     sample.iter().collect::<BinaryHeap<_>>().len();
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:33:19
+  --> tests/ui/needless_collect.rs:39:19
    |
 LL |     sample.iter().collect::<BinaryHeap<_>>().is_empty();
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:38:27
+  --> tests/ui/needless_collect.rs:44:27
    |
 LL |     let _ = sample.iter().collect::<HashSet<_>>().is_empty();
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:39:27
+  --> tests/ui/needless_collect.rs:45:27
    |
 LL |     let _ = sample.iter().collect::<HashSet<_>>().contains(&&0);
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `any(|x| x == &0)`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:61:27
+  --> tests/ui/needless_collect.rs:67:27
    |
 LL |     let _ = sample.iter().collect::<VecWrapper<_>>().is_empty();
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:62:27
+  --> tests/ui/needless_collect.rs:68:27
    |
 LL |     let _ = sample.iter().collect::<VecWrapper<_>>().contains(&&0);
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `any(|x| x == &0)`
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:66:40
+  --> tests/ui/needless_collect.rs:72:40
    |
 LL |         Vec::<u8>::new().extend((0..10).collect::<Vec<_>>());
    |                                        ^^^^^^^^^^^^^^^^^^^^ help: remove this call
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:67:20
+  --> tests/ui/needless_collect.rs:73:20
    |
 LL |         foo((0..10).collect::<Vec<_>>());
    |                    ^^^^^^^^^^^^^^^^^^^^ help: remove this call
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:68:49
+  --> tests/ui/needless_collect.rs:74:49
    |
 LL |         bar((0..10).collect::<Vec<_>>(), (0..10).collect::<Vec<_>>());
    |                                                 ^^^^^^^^^^^^^^^^^^^^ help: remove this call
 
 error: avoid using `collect()` when not needed
-  --> tests/ui/needless_collect.rs:69:37
+  --> tests/ui/needless_collect.rs:75:37
    |
 LL |         baz((0..10), (), ('a'..='z').collect::<Vec<_>>())
    |                                     ^^^^^^^^^^^^^^^^^^^^ help: remove this call

tests/ui/string_lit_chars_any.fixed

@@ -1,5 +1,11 @@
 //@aux-build:proc_macros.rs
-#![allow(clippy::eq_op, clippy::needless_raw_string_hashes, clippy::no_effect, unused)]
+#![allow(
+    clippy::eq_op,
+    clippy::needless_raw_string_hashes,
+    clippy::no_effect,
+    clippy::unused_any_all,
+    unused
+)]
 #![warn(clippy::string_lit_chars_any)]
 
 #[macro_use]

tests/ui/string_lit_chars_any.rs

@@ -1,5 +1,11 @@
 //@aux-build:proc_macros.rs
-#![allow(clippy::eq_op, clippy::needless_raw_string_hashes, clippy::no_effect, unused)]
+#![allow(
+    clippy::eq_op,
+    clippy::needless_raw_string_hashes,
+    clippy::no_effect,
+    clippy::unused_any_all,
+    unused
+)]
 #![warn(clippy::string_lit_chars_any)]
 
 #[macro_use]

tests/ui/string_lit_chars_any.stderr

@@ -1,5 +1,5 @@
 error: usage of `.chars().any(...)` to check if a char matches any from a string literal
-  --> tests/ui/string_lit_chars_any.rs:18:5
+  --> tests/ui/string_lit_chars_any.rs:24:5
    |
 LL |     "\\.+*?()|[]{}^$#&-~".chars().any(|x| x == c);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -12,7 +12,7 @@ LL |     matches!(c, '\\' | '.' | '+' | '*' | '?' | '(' | ')' | '|' | '[' | ']'
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: usage of `.chars().any(...)` to check if a char matches any from a string literal
-  --> tests/ui/string_lit_chars_any.rs:19:5
+  --> tests/ui/string_lit_chars_any.rs:25:5
    |
 LL |     r#"\.+*?()|[]{}^$#&-~"#.chars().any(|x| x == c);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -23,7 +23,7 @@ LL |     matches!(c, '\\' | '.' | '+' | '*' | '?' | '(' | ')' | '|' | '[' | ']'
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: usage of `.chars().any(...)` to check if a char matches any from a string literal
-  --> tests/ui/string_lit_chars_any.rs:20:5
+  --> tests/ui/string_lit_chars_any.rs:26:5
    |
 LL |     "\\.+*?()|[]{}^$#&-~".chars().any(|x| c == x);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -34,7 +34,7 @@ LL |     matches!(c, '\\' | '.' | '+' | '*' | '?' | '(' | ')' | '|' | '[' | ']'
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: usage of `.chars().any(...)` to check if a char matches any from a string literal
-  --> tests/ui/string_lit_chars_any.rs:21:5
+  --> tests/ui/string_lit_chars_any.rs:27:5
    |
 LL |     r#"\.+*?()|[]{}^$#&-~"#.chars().any(|x| c == x);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -45,7 +45,7 @@ LL |     matches!(c, '\\' | '.' | '+' | '*' | '?' | '(' | ')' | '|' | '[' | ']'
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: usage of `.chars().any(...)` to check if a char matches any from a string literal
-  --> tests/ui/string_lit_chars_any.rs:23:5
+  --> tests/ui/string_lit_chars_any.rs:29:5
    |
 LL |     "\\.+*?()|[]{}^$#&-~".chars().any(|x| { x == c });
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/unused_any_all.rs

@@ -0,0 +1,8 @@
+#![warn(clippy::unused_any_all)]
+
+fn main() {
+    (0..1).any(|_| false);
+    Iterator::any(&mut (0..1), |_| false);
+    let _ = (0..1).any(|_| false);
+    let _ = Iterator::any(&mut (0..1), |_| false);
+}