implementation of ex::const_iterator::operator[] was missing

diff --git a/ginac/ex.h b/ginac/ex.h
index ade1fd47179fa0c3bff757311517a38f14082fd1..97757baa2feebda0eb967505b0d40d7fc4cc0121 100644 (file)
--- a/ginac/ex.h
+++ b/ginac/ex.h
@@ -208,8 +208,9 @@ public:
                        return lhs.i - rhs.i;
                }
 
-               reference operator[](difference_type n) const
+               ex operator[](difference_type n) const
                {
+                       return bp->op(i + n);
                }
 
        protected: