Revert "[functions] adjust for playground removal"

This reverts commit d44a7fc7de788da73e6e0673a79c3116646bc6d3.

dune/stuff/functions.hh

@@ -19,6 +19,7 @@
 #include "functions/expression.hh"
 #include "functions/flattop.hh"
 #include "functions/ESV2007.hh"
+#include "playground/functions/indicator.hh"
 #include "functions/spe10.hh"
 
 namespace Dune {
@@ -146,6 +147,7 @@ private:
   typedef Functions::FlatTop<E, D, d, R, r, rC> FlattopType;
   typedef Functions::ESV2007::Testcase1Force<E, D, d, R, r, rC> ESV2007Testcase1ForceType;
   typedef Functions::ESV2007::Testcase1ExactSolution<E, D, d, R, r, rC> ESV2007Testcase1ExactSolutionType;
+  typedef Functions::Indicator<E, D, d, R, r, rC> IndicatorType;
   typedef Functions::Spe10::Model1<E, D, d, R, r, rC> Spe10Model1Type;
 
 public:
@@ -158,6 +160,7 @@ public:
     ret = call_append<FlattopType>(ret);
     ret = call_append<ESV2007Testcase1ForceType>(ret);
     ret = call_append<ESV2007Testcase1ExactSolutionType>(ret);
+    ret = call_append<IndicatorType>(ret);
     ret = call_append<Spe10Model1Type>(ret);
     return ret;
   } // ... available(...)
@@ -176,6 +179,8 @@ public:
       return call_default_config<ESV2007Testcase1ForceType>(sub_name);
     else if (call_compare<ESV2007Testcase1ExactSolutionType>(type))
       return call_default_config<ESV2007Testcase1ExactSolutionType>(sub_name);
+    else if (call_compare<IndicatorType>(type))
+      return call_default_config<IndicatorType>(sub_name);
     else if (call_compare<Spe10Model1Type>(type))
       return call_default_config<Spe10Model1Type>(sub_name);
     else if (available().empty())
@@ -210,6 +215,8 @@ public:
       return call_create<ESV2007Testcase1ForceType>(cfg);
     else if (call_compare<ESV2007Testcase1ExactSolutionType>(type))
       return call_create<ESV2007Testcase1ExactSolutionType>(cfg);
+    else if (call_compare<IndicatorType>(type))
+      return call_create<IndicatorType>(cfg);
     else if (call_compare<Spe10Model1Type>(type))
       return call_create<Spe10Model1Type>(cfg);
     else if (available().empty())