Auto merge of rust-lang#118692 - surechen:remove_unused_imports, r=petrochenkov

remove redundant imports

detects redundant imports that can be eliminated.

for rust-lang#117772 :

In order to facilitate review and modification, split the checking code and removing redundant imports code into two PR.

r? `@petrochenkov`

Author: bors

alloc/benches/btree/map.rs

@@ -1,6 +1,5 @@
 use std::collections::BTreeMap;
 use std::ops::RangeBounds;
-use std::vec::Vec;
 
 use rand::{seq::SliceRandom, Rng};
 use test::{black_box, Bencher};

alloc/benches/str.rs

@@ -1,4 +1,3 @@
-use core::iter::Iterator;
 use test::{black_box, Bencher};
 
 #[bench]

alloc/benches/vec_deque.rs

@@ -1,4 +1,3 @@
-use core::iter::Iterator;
 use std::{
     collections::{vec_deque, VecDeque},
     mem,

alloc/src/collections/binary_heap/tests.rs

@@ -1,8 +1,6 @@
 use super::*;
 use crate::boxed::Box;
 use crate::testing::crash_test::{CrashTestDummy, Panic};
-use core::mem;
-use std::iter::TrustedLen;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 
 #[test]

alloc/src/collections/btree/map/tests.rs

@@ -1,4 +1,3 @@
-use super::Entry::{Occupied, Vacant};
 use super::*;
 use crate::boxed::Box;
 use crate::fmt::Debug;
@@ -7,13 +6,9 @@ use crate::string::{String, ToString};
 use crate::testing::crash_test::{CrashTestDummy, Panic};
 use crate::testing::ord_chaos::{Cyclic3, Governed, Governor};
 use crate::testing::rng::DeterministicRng;
-use crate::vec::Vec;
 use core::assert_matches::assert_matches;
-use std::cmp::Ordering;
 use std::iter;
-use std::mem;
-use std::ops::Bound::{self, Excluded, Included, Unbounded};
-use std::ops::RangeBounds;
+use std::ops::Bound::{Excluded, Included, Unbounded};
 use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
 

alloc/src/collections/btree/set/tests.rs

@@ -1,9 +1,6 @@
 use super::*;
 use crate::testing::crash_test::{CrashTestDummy, Panic};
 use crate::testing::rng::DeterministicRng;
-use crate::vec::Vec;
-use std::cmp::Ordering;
-use std::hash::{Hash, Hasher};
 use std::ops::Bound::{Excluded, Included};
 use std::panic::{catch_unwind, AssertUnwindSafe};
 

alloc/src/ffi/c_str/tests.rs

@@ -1,6 +1,4 @@
 use super::*;
-use crate::rc::Rc;
-use crate::sync::Arc;
 use core::assert_matches::assert_matches;
 use core::ffi::FromBytesUntilNulError;
 use core::hash::{Hash, Hasher};

alloc/src/rc/tests.rs

@@ -1,12 +1,7 @@
 use super::*;
 
-use std::boxed::Box;
 use std::cell::RefCell;
 use std::clone::Clone;
-use std::convert::{From, TryInto};
-use std::mem::drop;
-use std::option::Option::{self, None, Some};
-use std::result::Result::{Err, Ok};
 
 #[test]
 fn test_clone() {

alloc/src/sync/tests.rs

@@ -1,21 +1,12 @@
 use super::*;
 
-use std::boxed::Box;
 use std::clone::Clone;
-use std::convert::{From, TryInto};
-use std::mem::drop;
-use std::ops::Drop;
-use std::option::Option::{self, None, Some};
-use std::sync::atomic::{
-    self,
-    Ordering::{Acquire, SeqCst},
-};
+use std::option::Option::None;
+use std::sync::atomic::Ordering::SeqCst;
 use std::sync::mpsc::channel;
 use std::sync::Mutex;
 use std::thread;
 
-use crate::vec::Vec;
-
 struct Canary(*mut atomic::AtomicUsize);
 
 impl Drop for Canary {

alloc/src/tests.rs

@@ -1,8 +1,6 @@
 //! Test for `boxed` mod.
 
 use core::any::Any;
-use core::clone::Clone;
-use core::convert::TryInto;
 use core::ops::Deref;
 
 use std::boxed::Box;