diff --git a/dlib/matrix/symmetric_matrix_cache_abstract.h b/dlib/matrix/symmetric_matrix_cache_abstract.h
index 9d8ec96d7..63ab347d7 100644
--- a/dlib/matrix/symmetric_matrix_cache_abstract.h
+++ b/dlib/matrix/symmetric_matrix_cache_abstract.h
@@ -54,46 +54,6 @@ namespace dlib
                       entire row/column/diagonal worth of data.  
     !*/
 
-// ----------------------------------------------------------------------------------------
-
-    template <typename EXP>
-    struct colm_exp
-    {
-        typedef matrix_op<op_colm<EXP> > type;
-    };
-
-    template <typename EXP>
-    struct rowm_exp
-    {
-        typedef matrix_op<op_rowm<EXP> > type;
-    };
-
-    template <typename EXP>
-    struct diag_exp
-    {
-        typedef matrix_op<op_diag<EXP> > type;
-    };
-
-// ----------------------------------------------------------------------------------------
-
-    template <typename EXP, typename cache_element_type>
-    struct colm_exp<matrix_op<op_symm_cache<EXP, cache_element_type> > >
-    {
-        typedef matrix_op<op_colm_symm_cache<EXP, cache_element_type> > type;
-    };
-
-    template <typename EXP, typename cache_element_type>
-    struct rowm_exp<matrix_op<op_symm_cache<EXP, cache_element_type> > >
-    {
-        typedef matrix_op<op_rowm_symm_cache<EXP, cache_element_type> > type;
-    };
-
-    template <typename EXP, typename cache_element_type>
-    struct diag_exp<matrix_op<op_symm_cache<EXP, cache_element_type> > >
-    {
-        typedef matrix_op<op_colm_symm_cache<EXP, cache_element_type> > type;
-    };
-
 // ----------------------------------------------------------------------------------------
 
 }