refactor: moved InPlaceDrop into in_place_drop.rs

library/alloc/src/vec/in_place_drop.rs

@@ -0,0 +1,24 @@
+use core::ptr::{self};
+use core::slice::{self};
+
+// A helper struct for in-place iteration that drops the destination slice of iteration,
+// i.e. the head. The source slice (the tail) is dropped by IntoIter.
+pub (super) struct InPlaceDrop<T> {
+    pub (super) inner: *mut T,
+    pub (super) dst: *mut T,
+}
+
+impl<T> InPlaceDrop<T> {
+    fn len(&self) -> usize {
+        unsafe { self.dst.offset_from(self.inner) as usize }
+    }
+}
+
+impl<T> Drop for InPlaceDrop<T> {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe {
+            ptr::drop_in_place(slice::from_raw_parts_mut(self.inner, self.len()));
+        }
+    }
+}

library/alloc/src/vec/mod.rs

@@ -113,6 +113,10 @@
 
 mod set_len_on_drop;
 
+use self::in_place_drop::InPlaceDrop;
+
+mod in_place_drop;
+
 /// A contiguous growable array type, written `Vec<T>` but pronounced 'vector'.
 ///
 /// # Examples
@@ -2233,28 +2237,6 @@ impl<T, I> SpecFromIter<T, I> for Vec<T>
     }
 }
 
-// A helper struct for in-place iteration that drops the destination slice of iteration,
-// i.e. the head. The source slice (the tail) is dropped by IntoIter.
-struct InPlaceDrop<T> {
-    inner: *mut T,
-    dst: *mut T,
-}
-
-impl<T> InPlaceDrop<T> {
-    fn len(&self) -> usize {
-        unsafe { self.dst.offset_from(self.inner) as usize }
-    }
-}
-
-impl<T> Drop for InPlaceDrop<T> {
-    #[inline]
-    fn drop(&mut self) {
-        unsafe {
-            ptr::drop_in_place(slice::from_raw_parts_mut(self.inner, self.len()));
-        }
-    }
-}
-
 impl<T> SpecFromIter<T, IntoIter<T>> for Vec<T> {
     fn from_iter(iterator: IntoIter<T>) -> Self {
         // A common case is passing a vector into a function which immediately