Rollup merge of #41135 - japaric:unstable-docs, r=steveklabnik

[rust.git] / src / librustc / mir / cache.rs

diff --git a/src/librustc/mir/cache.rs b/src/librustc/mir/cache.rs
index bc9bbebb1796a83627c3fe418ce934e395df3335..799686ceca4a0ec97021d7ed5343d0d24c417b7f 100644 (file)
--- a/src/librustc/mir/cache.rs
+++ b/src/librustc/mir/cache.rs
@@ -10,7 +10,9 @@
 
 use std::cell::{Ref, RefCell};
 use rustc_data_structures::indexed_vec::IndexVec;
-
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
+                                           StableHasherResult};
+use ich::StableHashingContext;
 use mir::{Mir, BasicBlock};
 
 use rustc_serialize as serialize;
@@ -33,6 +35,13 @@ fn decode<D: serialize::Decoder>(d: &mut D) -> Result<Self, D::Error> {
     }
 }
 
+impl<'a, 'tcx> HashStable<StableHashingContext<'a, 'tcx>> for Cache {
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          _: &mut StableHashingContext<'a, 'tcx>,
+                                          _: &mut StableHasher<W>) {
+        // do nothing
+    }
+}
 
 impl Cache {
     pub fn new() -> Self {