include guards

src/myblockproblem.hh

 // Based on dune/tnnmg/problem-classes/blocknonlineargsproblem.hh
 
+#ifndef MY_BLOCK_PROBLEM_HH
+#define MY_BLOCK_PROBLEM_HH
+
 // #include <dune/common/parametertree.hh>
 #include <dune/common/bitsetvector.hh>
 
@@ -140,3 +143,5 @@ class MyBlockProblem<MyConvexProblemTypeTEMPLATE>::IterateObject {
    * performed */
   int bisectionsteps;
 };
+
+#endif