diff --git a/ostream.cpp b/ostream.cpp
index 6543377..118509f 100644
--- a/ostream.cpp
+++ b/ostream.cpp
@@ -40,6 +40,24 @@ operator<< (std::ostream &os, VkExtent3D val)
 }
 
 
+//-----------------------------------------------------------------------------
+#if 0
+std::ostream&
+operator<< (std::ostream &os, VkQueueFlags val)
+{
+    const char *names[4] = {};
+    int cursor = 0;
+
+    if (val & VK_QUEUE_GRAPHICS_BIT)        names[cursor++] = "GRAPHICS";
+    if (val & VK_QUEUE_COMPUTE_BIT)         names[cursor++] = "COMPUTE";
+    if (val & VK_QUEUE_TRANSFER_BIT)        names[cursor++] = "TRANSFER";
+    if (val & VK_QUEUE_SPARSE_BINDING_BIT)  names[cursor++] = "SPARSE_BINDING";
+
+    return os << "[ " << util::make_infix (util::make_view (names, names + cursor)) << " ]";
+}
+#endif
+
+
 ///////////////////////////////////////////////////////////////////////////////
 static
 std::ostream&