Auto merge of #70800 - Dylan-DPC:rollup-9jjoptp, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #70635 (rustc_target: Some cleanup to `no_default_libraries`)
 - #70748 (Do not disable field reordering on enums with big discriminant)
 - #70752 (Add slice::fill)
 - #70766 (use ManuallyDrop instead of forget inside collections)
 - #70768 (macro_rules: `NtLifetime` cannot start with an identifier)
 - #70783 (comment refers to removed type)

Failed merges:

r? @ghost

1 files changed, 24 insertions, 0 deletions

diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index 9be52e2dfb0..66aad324618 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -23,6 +23,7 @@
 // * The `raw` and `bytes` submodules.
 // * Boilerplate trait implementations.
 
+use crate::borrow::Borrow;
 use crate::cmp;
 use crate::cmp::Ordering::{self, Equal, Greater, Less};
 use crate::fmt;
@@ -2145,6 +2146,29 @@ impl<T> [T] {
         }
     }
 
+    /// Fills `self` with elements by cloning `value`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(slice_fill)]
+    ///
+    /// let mut buf = vec![0; 10];
+    /// buf.fill(1);
+    /// assert_eq!(buf, vec![1; 10]);
+    /// ```
+    #[unstable(feature = "slice_fill", issue = "70758")]
+    pub fn fill<V>(&mut self, value: V)
+    where
+        V: Borrow<T>,
+        T: Clone,
+    {
+        let value = value.borrow();
+        for el in self {
+            el.clone_from(value)
+        }
+    }
+
     /// Copies the elements from `src` into `self`.
     ///
     /// The length of `src` must be the same as `self`.