xlist: add const versions of front / back

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/include/xlist.h b/src/include/xlist.h
index 1cbadc0262e3262393ae076f75b9ae0758df6d80..dcde2250d054f6c7127429ca017475ecc46c7ba8 100644 (file)
--- a/src/include/xlist.h
+++ b/src/include/xlist.h
@@ -137,7 +137,10 @@ public:
   }
 
   T front() { return static_cast<T>(_front->_item); }
+  const T front() const { return static_cast<const T>(_front->_item); }
+
   T back() { return static_cast<T>(_back->_item); }
+  const T back() const { return static_cast<const T>(_back->_item); }
 
   void pop_front() {
     assert(!empty());