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mainly as a TODO for myself to add something to Examples there as well

Author: antonilol

library/alloc/src/collections/vec_deque/mod.rs

@@ -1974,6 +1974,9 @@ impl<T, A: Allocator> VecDeque<T, A> {
     /// Prepends all contents of the iterator to the front of the deque.
     /// The order of the contents is preserved.
     ///
+    /// To get behavior like [`append`][VecDeque::append] where elements are moved
+    /// from the other collection to this one, use `self.prepend(other.drain())`.
+    ///
     /// # Examples
     ///
     /// ```