Fix unused variable warnings in step-31

diff --git a/examples/step-31/step-31.cc b/examples/step-31/step-31.cc
index 9dc71120aa1d28defdb60a51a53235aaa4f29de0..eedc92996632be243a530e8c0d1643d8c10d5fd8 100644 (file)
--- a/examples/step-31/step-31.cc
+++ b/examples/step-31/step-31.cc
@@ -178,6 +178,7 @@ namespace Step31
     TemperatureRightHandSide<dim>::value (const Point<dim>  &p,
                                           const unsigned int component) const
     {
+      (void) component;
       Assert (component == 0,
               ExcMessage ("Invalid operation for a scalar function."));