dont include archive.hpp, use template function

libsrc/general/ngarray.hpp

@@ -8,7 +8,6 @@
 /**************************************************************************/
 
 #include <core/array.hpp>
-#include <core/archive.hpp>
 
 namespace netgen
 {
@@ -423,8 +422,9 @@ namespace netgen
     }
 
     // Only provide this function if T is archivable
-    template<typename T2=T>
-    auto DoArchive(ngcore::Archive& archive) -> typename std::enable_if<ngcore::is_archivable<T2>, void>::type
+    template<typename ARCHIVE>
+    auto DoArchive(ARCHIVE& archive)
+      -> typename std::enable_if_t<ARCHIVE::template is_archivable<T>, void>
     {
       if(archive.Output())
         archive << size;

libsrc/gprim/geomobjects.hpp

@@ -7,7 +7,6 @@
 /* Date:   20. Jul. 02                                                     */
 /* *************************************************************************/
 
-#include <core/archive.hpp>
 #include <core/array.hpp>
 
 #include <general/ngarray.hpp>
@@ -72,7 +71,8 @@ namespace netgen
 
     operator const T* () const { return x; }
 
-    void DoArchive(Archive& archive)
+    template<typename ARCHIVE>
+    void DoArchive(ARCHIVE& archive)
     {
       for(int i=0; i<D; i++)
         archive & x[i];

libsrc/linalg/vector.hpp

@@ -7,11 +7,8 @@
 /* Date:   01. Oct. 94                                                     */
 /* *************************************************************************/
 
-#include <core/archive.hpp>
-
 namespace netgen
 {
-  using namespace ngcore;
 
 template <typename T>
 class TFlatVector
@@ -142,7 +139,8 @@ public:
   ~Vector ()
   { if (ownmem) delete [] data; }
 
-  virtual void DoArchive(Archive& ar)
+  template<typename ARCHIVE>
+  void DoArchive(ARCHIVE& ar)
   {
     auto size = s;
     ar & ownmem & size;