And another msvc fix..

src/hyteg/dgfunctionspace/DGFunction.hpp

@@ -269,6 +269,14 @@ class DGFunction final : public Function< DGFunction< ValueType > >
       WALBERLA_ABORT( "DGFunction::copyFrom() not implemented." );
    }
 
+   void swap( const DGFunction< ValueType >& other, const uint_t& level, const DoFType& flag = All ) const
+   {
+      WALBERLA_UNUSED( other );
+      WALBERLA_UNUSED( level );
+      WALBERLA_UNUSED( flag );
+      WALBERLA_ABORT( "DGFunction::swap() not implemented." )
+   }
+
  private:
    using Function< DGFunction< ValueType > >::communicators_;
    using Function< DGFunction< ValueType > >::additiveCommunicators_;

src/hyteg/p1functionspace/P1Operator.hpp

@@ -1954,7 +1954,7 @@ class P1Operator : public Operator< P1Function< real_t >, P1Function< real_t > >
       {
          auto neighborCell = storage_->getCell( edge_->neighborCells().at( neighborCellID ) );
          auto vertexAssemblyIndexInCell =
-             vertexdof::macroedge::getIndexInNeighboringMacroCell( { i, 0, 0 }, *edge_, neighborCellID, *storage_, level_ );
+             vertexdof::macroedge::getIndexInNeighboringMacroCell( { idx_t( i ), 0, 0 }, *edge_, neighborCellID, *storage_, level_ );
          edge_stencil[neighborCellID] = P1Elements::P1Elements3D::assembleP1LocalStencilNew_new< P1Form >(
              storage_, *neighborCell, vertexAssemblyIndexInCell, level_, form_ );
       }