2 files changed, 24 insertions, 0 deletions
diff --git a/src/libcore/collections.rs b/src/libcore/collections.rs
index 0bb9289397a..7d87e03c134 100644
--- a/src/libcore/collections.rs
+++ b/src/libcore/collections.rs
@@ -14,9 +14,23 @@
 /// knowledge known is the number of elements contained within.
 pub trait Collection {
     /// Return the number of elements in the container
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// let a = [1i, 2, 3];
+    /// assert_eq!(a.len(), 3);
+    /// ```
     fn len(&self) -> uint;
 
     /// Return true if the container contains no elements
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// let s = String::new();
+    /// assert!(s.is_empty());
+    /// ```
     #[inline]
     fn is_empty(&self) -> bool {
         self.len() == 0
diff --git a/src/libcore/default.rs b/src/libcore/default.rs
index 0fcc02aae0d..363d8ecf002 100644
--- a/src/libcore/default.rs
+++ b/src/libcore/default.rs
@@ -13,6 +13,16 @@
 /// A trait that types which have a useful default value should implement.
 pub trait Default {
     /// Return the "default value" for a type.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use std::default::Default;
+    ///
+    /// let i: i8 = Default::default();
+    /// let (x, y): (Option<String>, f64) = Default::default();
+    /// let (a, b, (c, d)): (int, uint, (bool, bool)) = Default::default();
+    /// ```
     fn default() -> Self;
 }