diff --git a/library/alloc/benches/vec.rs b/library/alloc/benches/vec.rs
index c9bdcaa78f3..91eec10d575 100644
--- a/library/alloc/benches/vec.rs
+++ b/library/alloc/benches/vec.rs
@@ -551,19 +551,13 @@ const LEN: usize = 16384;
 #[bench]
 fn bench_chain_collect(b: &mut Bencher) {
     let data = black_box([0; LEN]);
-    b.iter(|| data.iter().cloned().chain([1].iter().cloned()).collect::<Vec<_>>());
+    b.iter(|| data.iter().cloned().chain([1]).collect::<Vec<_>>());
 }
 
 #[bench]
 fn bench_chain_chain_collect(b: &mut Bencher) {
     let data = black_box([0; LEN]);
-    b.iter(|| {
-        data.iter()
-            .cloned()
-            .chain([1].iter().cloned())
-            .chain([2].iter().cloned())
-            .collect::<Vec<_>>()
-    });
+    b.iter(|| data.iter().cloned().chain([1]).chain([2]).collect::<Vec<_>>());
 }
 
 #[bench]
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index 105c60e7bf0..4a1d564e2ab 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -921,7 +921,7 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// ```
     /// let mut vec = Vec::with_capacity(10);
-    /// vec.extend([1, 2, 3].iter().cloned());
+    /// vec.extend([1, 2, 3]);
     /// assert_eq!(vec.capacity(), 10);
     /// vec.shrink_to_fit();
     /// assert!(vec.capacity() >= 3);
@@ -950,7 +950,7 @@ impl<T, A: Allocator> Vec<T, A> {
     /// ```
     /// #![feature(shrink_to)]
     /// let mut vec = Vec::with_capacity(10);
-    /// vec.extend([1, 2, 3].iter().cloned());
+    /// vec.extend([1, 2, 3]);
     /// assert_eq!(vec.capacity(), 10);
     /// vec.shrink_to(4);
     /// assert!(vec.capacity() >= 4);
@@ -984,7 +984,7 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// ```
     /// let mut vec = Vec::with_capacity(10);
-    /// vec.extend([1, 2, 3].iter().cloned());
+    /// vec.extend([1, 2, 3]);
     ///
     /// assert_eq!(vec.capacity(), 10);
     /// let slice = vec.into_boxed_slice();
@@ -2586,7 +2586,7 @@ impl<T, A: Allocator> Vec<T, A> {
     /// ```
     /// let mut v = vec![1, 2, 3];
     /// let new = [7, 8];
-    /// let u: Vec<_> = v.splice(..2, new.iter().cloned()).collect();
+    /// let u: Vec<_> = v.splice(..2, new).collect();
     /// assert_eq!(v, &[7, 8, 3]);
     /// assert_eq!(u, &[1, 2]);
     /// ```
diff --git a/library/alloc/src/vec/splice.rs b/library/alloc/src/vec/splice.rs
index 0a27b5b62ec..bad765c7f51 100644
--- a/library/alloc/src/vec/splice.rs
+++ b/library/alloc/src/vec/splice.rs
@@ -14,7 +14,7 @@ use super::{Drain, Vec};
 /// ```
 /// let mut v = vec![0, 1, 2];
 /// let new = [7, 8];
-/// let iter: std::vec::Splice<_> = v.splice(1.., new.iter().cloned());
+/// let iter: std::vec::Splice<_> = v.splice(1.., new);
 /// ```
 #[derive(Debug)]
 #[stable(feature = "vec_splice", since = "1.21.0")]
diff --git a/library/alloc/tests/vec.rs b/library/alloc/tests/vec.rs
index 36c81b49709..c203cdafecb 100644
--- a/library/alloc/tests/vec.rs
+++ b/library/alloc/tests/vec.rs
@@ -793,7 +793,7 @@ fn test_drain_leak() {
 fn test_splice() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    v.splice(2..4, a.iter().cloned());
+    v.splice(2..4, a);
     assert_eq!(v, &[1, 2, 10, 11, 12, 5]);
     v.splice(1..3, Some(20));
     assert_eq!(v, &[1, 20, 11, 12, 5]);
@@ -803,7 +803,7 @@ fn test_splice() {
 fn test_splice_inclusive_range() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    let t1: Vec<_> = v.splice(2..=3, a.iter().cloned()).collect();
+    let t1: Vec<_> = v.splice(2..=3, a).collect();
     assert_eq!(v, &[1, 2, 10, 11, 12, 5]);
     assert_eq!(t1, &[3, 4]);
     let t2: Vec<_> = v.splice(1..=2, Some(20)).collect();
@@ -816,7 +816,7 @@ fn test_splice_inclusive_range() {
 fn test_splice_out_of_bounds() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    v.splice(5..6, a.iter().cloned());
+    v.splice(5..6, a);
 }
 
 #[test]
@@ -824,7 +824,7 @@ fn test_splice_out_of_bounds() {
 fn test_splice_inclusive_out_of_bounds() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    v.splice(5..=5, a.iter().cloned());
+    v.splice(5..=5, a);
 }
 
 #[test]
@@ -848,7 +848,7 @@ fn test_splice_unbounded() {
 fn test_splice_forget() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    std::mem::forget(v.splice(2..4, a.iter().cloned()));
+    std::mem::forget(v.splice(2..4, a));
     assert_eq!(v, &[1, 2]);
 }
 
diff --git a/library/core/src/char/methods.rs b/library/core/src/char/methods.rs
index dcab2cd2d9d..2da3d6a72fb 100644
--- a/library/core/src/char/methods.rs
+++ b/library/core/src/char/methods.rs
@@ -58,7 +58,7 @@ impl char {
     /// ];
     ///
     /// assert_eq!(
-    ///     decode_utf16(v.iter().cloned())
+    ///     decode_utf16(v)
     ///         .map(|r| r.map_err(|e| e.unpaired_surrogate()))
     ///         .collect::<Vec<_>>(),
     ///     vec![
@@ -82,7 +82,7 @@ impl char {
     /// ];
     ///
     /// assert_eq!(
-    ///     decode_utf16(v.iter().cloned())
+    ///     decode_utf16(v)
     ///        .map(|r| r.unwrap_or(REPLACEMENT_CHARACTER))
     ///        .collect::<String>(),
     ///     "𝄞mus�ic�"
diff --git a/library/core/tests/array.rs b/library/core/tests/array.rs
index 42f44c23fe7..0ae625bdb68 100644
--- a/library/core/tests/array.rs
+++ b/library/core/tests/array.rs
@@ -1,4 +1,4 @@
-use core::array::{self, IntoIter};
+use core::array;
 use core::convert::TryFrom;
 
 #[test]
diff --git a/library/core/tests/iter/adapters/zip.rs b/library/core/tests/iter/adapters/zip.rs
index 000c15f72c8..797bfd957f9 100644
--- a/library/core/tests/iter/adapters/zip.rs
+++ b/library/core/tests/iter/adapters/zip.rs
@@ -236,9 +236,7 @@ fn test_zip_trusted_random_access_composition() {
 fn test_double_ended_zip() {
     let xs = [1, 2, 3, 4, 5, 6];
     let ys = [1, 2, 3, 7];
-    let a = xs.iter().cloned();
-    let b = ys.iter().cloned();
-    let mut it = a.zip(b);
+    let mut it = xs.iter().cloned().zip(ys);
     assert_eq!(it.next(), Some((1, 1)));
     assert_eq!(it.next(), Some((2, 2)));
     assert_eq!(it.next_back(), Some((4, 7)));