3 files changed, 3 insertions, 0 deletions
diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
index 4f24a8bb75a..0680b1fc329 100644
--- a/library/std/src/collections/hash/map.rs
+++ b/library/std/src/collections/hash/map.rs
@@ -448,6 +448,7 @@ impl<K, V, S> HashMap<K, V, S> {
     /// a.insert(1, "a");
     /// assert_eq!(a.len(), 1);
     /// ```
+    #[doc(alias = "length")]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn len(&self) -> usize {
         self.base.len()
diff --git a/library/std/src/collections/hash/set.rs b/library/std/src/collections/hash/set.rs
index 27093c1a077..f49e5801c35 100644
--- a/library/std/src/collections/hash/set.rs
+++ b/library/std/src/collections/hash/set.rs
@@ -199,6 +199,7 @@ impl<T, S> HashSet<T, S> {
     /// v.insert(1);
     /// assert_eq!(v.len(), 1);
     /// ```
+    #[doc(alias = "length")]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn len(&self) -> usize {
diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs
index 5d93016cadb..2eef4d58507 100644
--- a/library/std/src/ffi/os_str.rs
+++ b/library/std/src/ffi/os_str.rs
@@ -653,6 +653,7 @@ impl OsStr {
     /// let os_str = OsStr::new("foo");
     /// assert_eq!(os_str.len(), 3);
     /// ```
+    #[doc(alias = "length")]
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
     pub fn len(&self) -> usize {
         self.inner.inner.len()