changed cmake to prevent compiling of std::variant examples if no variant is available

src/CMakeLists.txt

@@ -10,11 +10,14 @@ target_link_dune_default_libraries("localrefinement")
 add_executable("uggrid" uggrid.cc)
 target_link_dune_default_libraries("uggrid")
 
-add_executable("multigridview" multigridview.cc)
-target_link_dune_default_libraries("multigridview")
+if (DUNE_HAVE_CXX_VARIANT)
+  add_executable("multigridview" multigridview.cc)
+  target_link_dune_default_libraries("multigridview")
+
+  add_executable("hierarchiciterator" hierarchiciterator.cc)
+  target_link_dune_default_libraries("hierarchiciterator")
+endif (DUNE_HAVE_CXX_VARIANT)
 
-add_executable("hierarchiciterator" hierarchiciterator.cc)
-target_link_dune_default_libraries("hierarchiciterator")
 
 add_executable("interpolate" interpolate.cc)
 target_link_dune_default_libraries("interpolate")

src/phasefield4.cc

@@ -39,7 +39,7 @@
 
 #include <dune/functions/gridfunctions/discreteglobalbasisfunction.hh>
 
-#include "phasefield3.hh"
+#include "phasefield4.hh"
 
 using namespace Dune;
 using namespace Dune::Indices;