Move from cmp --> eq, and provide a good implementation for interning
diff --git a/include/grpc/impl/codegen/slice.h b/include/grpc/impl/codegen/slice.h
index ecce1ca..fbd18e6 100644
--- a/include/grpc/impl/codegen/slice.h
+++ b/include/grpc/impl/codegen/slice.h
@@ -57,7 +57,8 @@
 typedef struct grpc_slice_refcount_vtable {
   void (*ref)(void *);
   void (*unref)(grpc_exec_ctx *exec_ctx, void *);
-  uint32_t (*hash)(void *, grpc_slice slice);
+  int (*eq)(grpc_slice a, grpc_slice b);
+  uint32_t (*hash)(grpc_slice slice);
 } grpc_slice_refcount_vtable;
 
 /* Reference count container for grpc_slice. Contains function pointers to