Move hash module from collections to core

src/liballoc/boxed.rs

@@ -15,6 +15,7 @@ use core::clone::Clone;
 use core::cmp::{PartialEq, PartialOrd, Eq, Ord, Ordering};
 use core::default::Default;
 use core::fmt;
+use core::hash::{mod, Hash};
 use core::kinds::Sized;
 use core::mem;
 use core::option::Option;
@@ -93,6 +94,14 @@ impl<Sized? T: Ord> Ord for Box<T> {
 }
 impl<Sized? T: Eq> Eq for Box<T> {}
 
+impl<S: hash::Writer, Sized? T: Hash<S>> Hash<S> for Box<T> {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (**self).hash(state);
+    }
+}
+
+
 /// Extension methods for an owning `Any` trait object.
 #[unstable = "post-DST and coherence changes, this will not be a trait but \
               rather a direct `impl` on `Box<Any>`"]

src/liballoc/lib.rs

@@ -64,7 +64,7 @@
        html_root_url = "http://doc.rust-lang.org/nightly/")]
 
 #![no_std]
-#![feature(lang_items, phase, unsafe_destructor)]
+#![feature(lang_items, phase, unsafe_destructor, default_type_params)]
 
 #[phase(plugin, link)]
 extern crate core;

src/liballoc/rc.rs

@@ -147,6 +147,7 @@ use core::clone::Clone;
 use core::cmp::{PartialEq, PartialOrd, Eq, Ord, Ordering};
 use core::default::Default;
 use core::fmt;
+use core::hash::{mod, Hash};
 use core::kinds::marker;
 use core::mem::{transmute, min_align_of, size_of, forget};
 use core::ops::{Deref, Drop};
@@ -594,6 +595,14 @@ impl<T: Ord> Ord for Rc<T> {
     fn cmp(&self, other: &Rc<T>) -> Ordering { (**self).cmp(&**other) }
 }
 
+// FIXME (#18248) Make `T` `Sized?`
+impl<S: hash::Writer, T: Hash<S>> Hash<S> for Rc<T> {
+    #[inline]
+    fn hash(&self, state: &mut S) {
+        (**self).hash(state);
+    }
+}
+
 #[experimental = "Show is experimental."]
 impl<T: fmt::Show> fmt::Show for Rc<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {