Auto merge of #57354 - kennytm:rollup, r=kennytm

Rollup of 17 pull requests

Successful merges:

 - #57219 (Remove some unused code)
 - #57229 (Fix #56806 by using `delay_span_bug` in object safety layout sanity checks)
 - #57233 (Rename and fix nolink-with-link-args test)
 - #57238 (Fix backtraces for inlined functions on Windows)
 - #57249 (Fix broken links to second edition TRPL.)
 - #57267 (src/jemalloc is gone, remove its mention from COPYRIGHT)
 - #57273 (Update the stdsimd submodule)
 - #57278 (Add Clippy to config.toml.example)
 - #57295 (Fix 'be be' constructs)
 - #57311 (VaList::copy should not require a mutable ref)
 - #57312 (`const fn` is no longer coming soon (const keyword docs))
 - #57313 (Improve Box<T> -> Pin<Box<T>> conversion)
 - #57314 (Fix repeated word typos)
 - #57326 (Doc rewording, use the same name `writer`)
 - #57338 (rustdoc: force binary filename for compiled doctests)
 - #57342 (librustc_mir: Make qualify_min_const_fn module public)
 - #57343 (Calculate privacy access only via query)

Failed merges:

 - #57340 (Use correct tracking issue for c_variadic)

r? @ghost

1 files changed, 15 insertions, 5 deletions

diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index fbd0b948b82..1c459f5c425 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -257,6 +257,19 @@ impl<T: ?Sized> Box<T> {
     {
         unsafe { &mut *Box::into_raw(b) }
     }
+
+    /// Converts a `Box<T>` into a `Pin<Box<T>>`
+    ///
+    /// This conversion does not allocate on the heap and happens in place.
+    ///
+    /// This is also available via [`From`].
+    #[unstable(feature = "box_into_pin", issue = "0")]
+    pub fn into_pin(boxed: Box<T>) -> Pin<Box<T>> {
+        // It's not possible to move or replace the insides of a `Pin<Box<T>>`
+        // when `T: !Unpin`,  so it's safe to pin it directly without any
+        // additional requirements.
+        unsafe { Pin::new_unchecked(boxed) }
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -451,15 +464,12 @@ impl<T> From<T> for Box<T> {
 }
 
 #[stable(feature = "pin", since = "1.33.0")]
-impl<T> From<Box<T>> for Pin<Box<T>> {
+impl<T: ?Sized> From<Box<T>> for Pin<Box<T>> {
     /// Converts a `Box<T>` into a `Pin<Box<T>>`
     ///
     /// This conversion does not allocate on the heap and happens in place.
     fn from(boxed: Box<T>) -> Self {
-        // It's not possible to move or replace the insides of a `Pin<Box<T>>`
-        // when `T: !Unpin`,  so it's safe to pin it directly without any
-        // additional requirements.
-        unsafe { Pin::new_unchecked(boxed) }
+        Box::into_pin(boxed)
     }
 }