diff --git a/src/TNL/Containers/Segments/CSRView.h b/src/TNL/Containers/Segments/CSRView.h
new file mode 100644
index 0000000000000000000000000000000000000000..5eeb7ecb3efafb5258f9100505874df4f8322538
--- /dev/null
+++ b/src/TNL/Containers/Segments/CSRView.h
@@ -0,0 +1,105 @@
+/***************************************************************************
+ CSRView.h - description
+ -------------------
+ begin : Dec 11, 2019
+ copyright : (C) 2019 by Tomas Oberhuber
+ email : tomas.oberhuber@fjfi.cvut.cz
+ ***************************************************************************/
+
+/* See Copyright Notice in tnl/Copyright */
+
+#pragma once
+
+#include <TNL/Containers/Vector.h>
+
+namespace TNL {
+ namespace Containers {
+ namespace Segments {
+
+template< typename Device,
+ typename Index >
+class CSRView
+{
+ public:
+
+ using DeviceType = Device;
+ using IndexType = Index;
+ using OffsetsHolderView = typedef Containers::Vector< IndexType, DeviceType, IndexType >::ViewType;
+
+ __cuda_callable__
+ CSRView();
+
+ __cuda_callable__
+ CSRView( const OffsetsHolderView& offsets );
+
+ __cuda_callable__
+ CSRView( const CSRView& csr_view );
+
+ __cuda_callable__
+ CSRView( const CSRView&& csr_view );
+
+ /**
+ * \brief Number segments.
+ */
+ __cuda_callable__
+ IndexType getSegmentsCount() const;
+
+ /***
+ * \brief Returns size of the segment number \r segmentIdx
+ */
+ __cuda_callable__
+ IndexType getSegmentSize( const IndexType segmentIdx ) const;
+
+ /***
+ * \brief Returns number of elements managed by all segments.
+ */
+ __cuda_callable__
+ IndexType getSize() const;
+
+ /***
+ * \brief Returns number of elements that needs to be allocated.
+ */
+ __cuda_callable__
+ IndexType getStorageSize() const;
+
+ __cuda_callable__
+ IndexType getGlobalIndex( const Index segmentIdx, const Index localIdx ) const;
+
+ __cuda_callable__
+ void getSegmentAndLocalIndex( const Index globalIdx, Index& segmentIdx, Index& localIdx ) const;
+
+ /***
+ * \brief Go over all segments and for each segment element call
+ * function 'f' with arguments 'args'. The return type of 'f' is bool.
+ * When its true, the for-loop continues. Once 'f' returns false, the for-loop
+ * is terminated.
+ */
+ template< typename Function, typename... Args >
+ void forSegments( IndexType first, IndexType last, Function& f, Args... args ) const;
+
+ template< typename Function, typename... Args >
+ void forAll( Function& f, Args... args ) const;
+
+
+ /***
+ * \brief Go over all segments and perform a reduction in each of them.
+ */
+ template< typename Fetch, typename Reduction, typename ResultKeeper, typename Real, typename... Args >
+ void segmentsReduction( IndexType first, IndexType last, Fetch& fetch, Reduction& reduction, ResultKeeper& keeper, const Real& zero, Args... args ) const;
+
+ template< typename Fetch, typename Reduction, typename ResultKeeper, typename Real, typename... Args >
+ void allReduction( Fetch& fetch, Reduction& reduction, ResultKeeper& keeper, const Real& zero, Args... args ) const;
+
+ void save( File& file ) const;
+
+ void load( File& file );
+
+ protected:
+
+ OffsetsHolderView offsets;
+};
+ } // namespace Segements
+ } // namespace Conatiners
+} // namespace TNL
+
+#include <TNL/Containers/Segments/CSRView.hpp>
diff --git a/src/TNL/Containers/Segments/CSRView.hpp b/src/TNL/Containers/Segments/CSRView.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..30ed24071e7b42b8cd27cf959e890366682319ed
--- /dev/null
+++ b/src/TNL/Containers/Segments/CSRView.hpp
@@ -0,0 +1,221 @@
+/***************************************************************************
+ CSRView.hpp - description
+ -------------------
+ begin : Dec 11, 2019
+ copyright : (C) 2019 by Tomas Oberhuber
+ email : tomas.oberhuber@fjfi.cvut.cz
+ ***************************************************************************/
+
+/* See Copyright Notice in tnl/Copyright */
+
+#pragma once
+
+#include <TNL/Containers/Vector.h>
+#include <TNL/Algorithms/ParallelFor.h>
+#include <TNL/Containers/Segments/CSRView.h>
+
+namespace TNL {
+ namespace Containers {
+ namespace Segments {
+
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+CSRView< Device, Index >::
+CSRView()
+{
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+CSRView< Device, Index >::
+CSRView( const OffsetsHolderView& offsets_view )
+ : offsets( offsets_view )
+{
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+CSRView< Device, Index >::
+CSRView( const CSRView& csr_view )
+ : offsets( csr_view.offsest )
+{
+
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+CSRView< Device, Index >::
+CSRView( const CSRView&& csr_view )
+ : offsets( std::move( csr_view.offsest ) )
+{
+
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+Index
+CSRView< Device, Index >::
+getSegmentsCount() const
+{
+ return this->offsets.getSize() - 1;
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+Index
+CSRView< Device, Index >::
+getSegmentSize( const IndexType segmentIdx ) const
+{
+ if( ! std::is_same< DeviceType, Devices::Host >::value )
+ {
+#ifdef __CUDA_ARCH__
+ return offsets[ segmentIdx + 1 ] - offsets[ segmentIdx ];
+#else
+ return offsets.getElement( segmentIdx + 1 ) - offsets.getElement( segmentIdx );
+#endif
+ }
+ return offsets[ segmentIdx + 1 ] - offsets[ segmentIdx ];
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+Index
+CSRView< Device, Index >::
+getSize() const
+{
+ return this->getStorageSize();
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+Index
+CSRView< Device, Index >::
+getStorageSize() const
+{
+ if( ! std::is_same< DeviceType, Devices::Host >::value )
+ {
+#ifdef __CUDA_ARCH__
+ return offsets[ this->getSegmentsCount() ];
+#else
+ return offsets.getElement( this->getSegmentsCount() );
+#endif
+ }
+ return offsets[ this->getSegmentsCount() ];
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+Index
+CSRView< Device, Index >::
+getGlobalIndex( const Index segmentIdx, const Index localIdx ) const
+{
+ if( ! std::is_same< DeviceType, Devices::Host >::value )
+ {
+#ifdef __CUDA_ARCH__
+ return offsets[ segmentIdx ] + localIdx;
+#else
+ return offsets.getElement( segmentIdx ) + localIdx;
+#endif
+ }
+ return offsets[ segmentIdx ] + localIdx;
+}
+
+template< typename Device,
+ typename Index >
+__cuda_callable__
+void
+CSRView< Device, Index >::
+getSegmentAndLocalIndex( const Index globalIdx, Index& segmentIdx, Index& localIdx ) const
+{
+}
+
+template< typename Device,
+ typename Index >
+ template< typename Function, typename... Args >
+void
+CSRView< Device, Index >::
+forSegments( IndexType first, IndexType last, Function& f, Args... args ) const
+{
+ const auto offsetsView = this->offsets.getConstView();
+ auto l = [=] __cuda_callable__ ( const IndexType segmentIdx, Args... args ) mutable {
+ const IndexType begin = offsetsView[ segmentIdx ];
+ const IndexType end = offsetsView[ segmentIdx + 1 ];
+ IndexType localIdx( 0 );
+ for( IndexType globalIdx = begin; globalIdx < end; globalIdx++ )
+ if( ! f( segmentIdx, localIdx++, globalIdx, args... ) )
+ break;
+ };
+ Algorithms::ParallelFor< Device >::exec( first, last, l, args... );
+}
+
+template< typename Device,
+ typename Index >
+ template< typename Function, typename... Args >
+void
+CSRView< Device, Index >::
+forAll( Function& f, Args... args ) const
+{
+ this->forSegments( 0, this->getSize(), f, args... );
+}
+
+template< typename Device,
+ typename Index >
+ template< typename Fetch, typename Reduction, typename ResultKeeper, typename Real, typename... Args >
+void
+CSRView< Device, Index >::
+segmentsReduction( IndexType first, IndexType last, Fetch& fetch, Reduction& reduction, ResultKeeper& keeper, const Real& zero, Args... args ) const
+{
+ using RealType = decltype( fetch( IndexType(), IndexType() ) );
+ const auto offsetsView = this->offsets.getConstView();
+ auto l = [=] __cuda_callable__ ( const IndexType i, Args... args ) mutable {
+ const IndexType begin = offsetsView[ i ];
+ const IndexType end = offsetsView[ i + 1 ];
+ RealType aux( zero );
+ for( IndexType j = begin; j < end; j++ )
+ reduction( aux, fetch( i, j, args... ) );
+ keeper( i, aux );
+ };
+ Algorithms::ParallelFor< Device >::exec( first, last, l, args... );
+}
+
+template< typename Device,
+ typename Index >
+ template< typename Fetch, typename Reduction, typename ResultKeeper, typename Real, typename... Args >
+void
+CSRView< Device, Index >::
+allReduction( Fetch& fetch, Reduction& reduction, ResultKeeper& keeper, const Real& zero, Args... args ) const
+{
+ this->segmentsReduction( 0, this->getSegmentsCount(), fetch, reduction, keeper, zero, args... );
+}
+
+template< typename Device,
+ typename Index >
+void
+CSRView< Device, Index >::
+save( File& file ) const
+{
+ file << this->offsets;
+}
+
+template< typename Device,
+ typename Index >
+void
+CSRView< Device, Index >::
+load( File& file )
+{
+ file >> this->offsets;
+}
+
+ } // namespace Segments
+ } // namespace Conatiners
+} // namespace TNL