Add inclusion guards around instantiation that requires OpenCascade.

diff --git a/source/gmsh/utilities.cc b/source/gmsh/utilities.cc
index 2f363bdc01ce07f3983f7d5c500daed100c3200e..e65d89c3bacd819e36c199689516dc0c5ff8a2d2 100644 (file)
--- a/source/gmsh/utilities.cc
+++ b/source/gmsh/utilities.cc
@@ -119,7 +119,10 @@ namespace Gmsh
   }
 #endif
 
+  // explicit instantiations
+#ifdef DEAL_II_WITH_OPENCASCADE
 #include "utilities.inst"
+#endif
 }
 
 DEAL_II_NAMESPACE_CLOSE