Declare the existence of explicit instantiations.

diff --git a/include/deal.II/hp/mapping_collection.h b/include/deal.II/hp/mapping_collection.h
index 650a54d29616184fa49aa2ca5a8b88713b2181d7..c1c22feef7a6a60d6d2b555d8311a5a2c27e45eb 100644 (file)
--- a/include/deal.II/hp/mapping_collection.h
+++ b/include/deal.II/hp/mapping_collection.h
@@ -152,6 +152,7 @@ namespace hp
   };
 
 
+
   /* --------------- inline functions ------------------- */
 
   template <int dim, int spacedim>
@@ -180,6 +181,19 @@ namespace hp
     StaticMappingQ1<dim, spacedim>::mapping_collection =
       MappingCollection<dim, spacedim>(MappingQ1<dim, spacedim>{});
 
+
+#ifndef DOXYGEN
+  // Declare the existence of explicit instantiations of the class
+  // above to avoid certain warnings issues by clang and
+  // newer (LLVM-based) Intel compilers:
+  extern template struct StaticMappingQ1<1, 1>;
+  extern template struct StaticMappingQ1<1, 2>;
+  extern template struct StaticMappingQ1<1, 3>;
+  extern template struct StaticMappingQ1<2, 2>;
+  extern template struct StaticMappingQ1<2, 3>;
+  extern template struct StaticMappingQ1<3, 3>;
+#endif
+
 } // namespace hp