auto merge of #18475 : gamazeps/rust/toExtend, r=alexcrichton

Ensured that Extend & FromIterator are implemented for the libcollection.

Removed the fact that FromIterator had to be implemented in order to implement Extend, as it did not make sense for LruCache (it needs to be given a size and there are no Default for LruCache).

Changed the name from Extend to Extendable.

Part of #18424 

1 files changed, 16 insertions, 0 deletions

diff --git a/src/libcollections/enum_set.rs b/src/libcollections/enum_set.rs
index 68991628b22..b13e45099ee 100644
--- a/src/libcollections/enum_set.rs
+++ b/src/libcollections/enum_set.rs
@@ -235,6 +235,22 @@ impl<E:CLike> Iterator<E> for Items<E> {
     }
 }
 
+impl<E:CLike> FromIterator<E> for EnumSet<E> {
+    fn from_iter<I:Iterator<E>>(iterator: I) -> EnumSet<E> {
+        let mut ret = EnumSet::new();
+        ret.extend(iterator);
+        ret
+    }
+}
+
+impl<E:CLike> Extend<E> for EnumSet<E> {
+    fn extend<I: Iterator<E>>(&mut self, mut iterator: I) {
+        for element in iterator {
+            self.insert(element);
+        }
+    }
+}
+
 #[cfg(test)]
 mod test {
     use std::prelude::*;