1 files changed, 24 insertions, 0 deletions
diff --git a/libcollections/linked_list.rs b/libcollections/linked_list.rs
index 85a4fa8..406b979 100644
--- a/libcollections/linked_list.rs
+++ b/libcollections/linked_list.rs
@@ -30,6 +30,8 @@ use core::mem;
 use core::ops::{BoxPlace, InPlace, Place, Placer};
 use core::ptr::{self, Shared};
 
+use super::SpecExtend;
+
 /// A doubly-linked list.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct LinkedList<T> {
@@ -401,6 +403,16 @@ impl<T> LinkedList<T> {
         *self = LinkedList::new()
     }
 
+    /// Returns `true` if the `LinkedList` contains an element equal to the
+    /// given value.
+    #[unstable(feature = "linked_list_contains", reason = "recently added",
+               issue = "32630")]
+    pub fn contains(&self, x: &T) -> bool
+        where T: PartialEq<T>
+    {
+        self.iter().any(|e| e == x)
+    }
+
     /// Provides a reference to the front element, or `None` if the list is
     /// empty.
     ///
@@ -969,12 +981,24 @@ impl<'a, T> IntoIterator for &'a mut LinkedList<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<A> Extend<A> for LinkedList<A> {
     fn extend<T: IntoIterator<Item = A>>(&mut self, iter: T) {
+        <Self as SpecExtend<T>>::spec_extend(self, iter);
+    }
+}
+
+impl<I: IntoIterator> SpecExtend<I> for LinkedList<I::Item> {
+    default fn spec_extend(&mut self, iter: I) {
         for elt in iter {
             self.push_back(elt);
         }
     }
 }
 
+impl<T> SpecExtend<LinkedList<T>> for LinkedList<T> {
+    fn spec_extend(&mut self, ref mut other: LinkedList<T>) {
+        self.append(other);
+    }
+}
+
 #[stable(feature = "extend_ref", since = "1.2.0")]
 impl<'a, T: 'a + Copy> Extend<&'a T> for LinkedList<T> {
     fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) {