Rollup merge of #72811 - pickfire:liballoc-impl, r=Amanieu

Liballoc impl

Mainly code rearrangements

src/liballoc/raw_vec.rs

@@ -118,6 +118,30 @@ pub fn from_box(slice: Box<[T]>) -> Self {
             RawVec::from_raw_parts(slice.as_mut_ptr(), slice.len())
         }
     }
+
+    /// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
+    ///
+    /// Note that this will correctly reconstitute any `cap` changes
+    /// that may have been performed. (See description of type for details.)
+    ///
+    /// # Safety
+    ///
+    /// * `len` must be greater than or equal to the most recently requested capacity, and
+    /// * `len` must be less than or equal to `self.capacity()`.
+    ///
+    /// Note, that the requested capacity and `self.capacity()` could differ, as
+    /// an allocator could overallocate and return a greater memory block than requested.
+    pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>]> {
+        // Sanity-check one half of the safety requirement (we cannot check the other half).
+        debug_assert!(
+            len <= self.capacity(),
+            "`len` must be smaller than or equal to `self.capacity()`"
+        );
+
+        let me = ManuallyDrop::new(self);
+        let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
+        Box::from_raw(slice)
+    }
 }
 
 impl<T, A: AllocRef> RawVec<T, A> {
@@ -520,32 +544,6 @@ fn finish_grow<A>(
     Ok(memory)
 }
 
-impl<T> RawVec<T, Global> {
-    /// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
-    ///
-    /// Note that this will correctly reconstitute any `cap` changes
-    /// that may have been performed. (See description of type for details.)
-    ///
-    /// # Safety
-    ///
-    /// * `len` must be greater than or equal to the most recently requested capacity, and
-    /// * `len` must be less than or equal to `self.capacity()`.
-    ///
-    /// Note, that the requested capacity and `self.capacity()` could differ, as
-    /// an allocator could overallocate and return a greater memory block than requested.
-    pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>]> {
-        // Sanity-check one half of the safety requirement (we cannot check the other half).
-        debug_assert!(
-            len <= self.capacity(),
-            "`len` must be smaller than or equal to `self.capacity()`"
-        );
-
-        let me = ManuallyDrop::new(self);
-        let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
-        Box::from_raw(slice)
-    }
-}
-
 unsafe impl<#[may_dangle] T, A: AllocRef> Drop for RawVec<T, A> {
     /// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
     fn drop(&mut self) {

src/liballoc/vec.rs

@@ -1905,6 +1905,22 @@ fn is_zero(&self) -> bool {
 // Common trait implementations for Vec
 ////////////////////////////////////////////////////////////////////////////////
 
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T> ops::Deref for Vec<T> {
+    type Target = [T];
+
+    fn deref(&self) -> &[T] {
+        unsafe { slice::from_raw_parts(self.as_ptr(), self.len) }
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T> ops::DerefMut for Vec<T> {
+    fn deref_mut(&mut self) -> &mut [T] {
+        unsafe { slice::from_raw_parts_mut(self.as_mut_ptr(), self.len) }
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Clone> Clone for Vec<T> {
     #[cfg(not(test))]
@@ -1960,22 +1976,6 @@ fn index_mut(&mut self, index: I) -> &mut Self::Output {
     }
 }
 
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<T> ops::Deref for Vec<T> {
-    type Target = [T];
-
-    fn deref(&self) -> &[T] {
-        unsafe { slice::from_raw_parts(self.as_ptr(), self.len) }
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<T> ops::DerefMut for Vec<T> {
-    fn deref_mut(&mut self) -> &mut [T] {
-        unsafe { slice::from_raw_parts_mut(self.as_mut_ptr(), self.len) }
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> FromIterator<T> for Vec<T> {
     #[inline]