auto merge of #10658 : LeoTestard/rust/serialize-rc, r=cmr

Implement various traits (IterBytes and extra's Encodable and Decodable) for Rc<T> when T alreay implements the trait.

src/libextra/serialize.rs

@@ -20,6 +20,7 @@ Core encoding and decoding interfaces.
 
 use std::at_vec;
 use std::hashmap::{HashMap, HashSet};
+use std::rc::Rc;
 use std::trie::{TrieMap, TrieSet};
 use std::vec;
 use ringbuf::RingBuf;
@@ -405,6 +406,20 @@ impl<S:Encoder,T:Encodable<S>> Encodable<S> for @T {
     }
 }
 
+impl<S:Encoder,T:Encodable<S> + Freeze> Encodable<S> for Rc<T> {
+    #[inline]
+    fn encode(&self, s: &mut S) {
+        self.borrow().encode(s)
+    }
+}
+
+impl<D:Decoder,T:Decodable<D> + Freeze> Decodable<D> for Rc<T> {
+    #[inline]
+    fn decode(d: &mut D) -> Rc<T> {
+        Rc::new(Decodable::decode(d))
+    }
+}
+
 impl<D:Decoder,T:Decodable<D> + 'static> Decodable<D> for @T {
     fn decode(d: &mut D) -> @T {
         @Decodable::decode(d)

src/libstd/to_bytes.rs

@@ -18,6 +18,7 @@ use cast;
 use container::Container;
 use iter::Iterator;
 use option::{None, Option, Some};
+use rc::Rc;
 use str::{Str, StrSlice};
 use vec::{Vector, ImmutableVector};
 
@@ -325,6 +326,13 @@ impl<A:IterBytes> IterBytes for @mut A {
     }
 }
 
+impl<A:IterBytes> IterBytes for Rc<A> {
+    #[inline]
+    fn iter_bytes(&self, lsb0: bool, f: Cb) -> bool {
+        self.borrow().iter_bytes(lsb0, f)
+    }
+}
+
 impl<A:IterBytes> IterBytes for ~A {
     #[inline]
     fn iter_bytes(&self, lsb0: bool, f: Cb) -> bool {