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diff --git a/third_party/eigen3/Eigen/src/SparseCore/SparseView.h b/third_party/eigen3/Eigen/src/SparseCore/SparseView.h
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+++ b/third_party/eigen3/Eigen/src/SparseCore/SparseView.h
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+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr>
+// Copyright (C) 2010 Daniel Lowengrub <lowdanie@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef EIGEN_SPARSEVIEW_H
+#define EIGEN_SPARSEVIEW_H
+
+namespace Eigen { 
+
+namespace internal {
+
+template<typename MatrixType>
+struct traits<SparseView<MatrixType> > : traits<MatrixType>
+{
+  typedef typename MatrixType::Index Index;
+  typedef Sparse StorageKind;
+  enum {
+    Flags = int(traits<MatrixType>::Flags) & (RowMajorBit)
+  };
+};
+
+} // end namespace internal
+
+template<typename MatrixType>
+class SparseView : public SparseMatrixBase<SparseView<MatrixType> >
+{
+  typedef typename MatrixType::Nested MatrixTypeNested;
+  typedef typename internal::remove_all<MatrixTypeNested>::type _MatrixTypeNested;
+public:
+  EIGEN_SPARSE_PUBLIC_INTERFACE(SparseView)
+
+  SparseView(const MatrixType& mat, const Scalar& m_reference = Scalar(0),
+             typename NumTraits<Scalar>::Real m_epsilon = NumTraits<Scalar>::dummy_precision()) : 
+    m_matrix(mat), m_reference(m_reference), m_epsilon(m_epsilon) {}
+
+  class InnerIterator;
+
+  inline Index rows() const { return m_matrix.rows(); }
+  inline Index cols() const { return m_matrix.cols(); }
+
+  inline Index innerSize() const { return m_matrix.innerSize(); }
+  inline Index outerSize() const { return m_matrix.outerSize(); }
+
+protected:
+  MatrixTypeNested m_matrix;
+  Scalar m_reference;
+  typename NumTraits<Scalar>::Real m_epsilon;
+};
+
+template<typename MatrixType>
+class SparseView<MatrixType>::InnerIterator : public _MatrixTypeNested::InnerIterator
+{
+  typedef typename SparseView::Index Index;
+public:
+  typedef typename _MatrixTypeNested::InnerIterator IterBase;
+  InnerIterator(const SparseView& view, Index outer) :
+  IterBase(view.m_matrix, outer), m_view(view)
+  {
+    incrementToNonZero();
+  }
+
+  EIGEN_STRONG_INLINE InnerIterator& operator++()
+  {
+    IterBase::operator++();
+    incrementToNonZero();
+    return *this;
+  }
+
+  using IterBase::value;
+
+protected:
+  const SparseView& m_view;
+
+private:
+  void incrementToNonZero()
+  {
+    while((bool(*this)) && internal::isMuchSmallerThan(value(), m_view.m_reference, m_view.m_epsilon))
+    {
+      IterBase::operator++();
+    }
+  }
+};
+
+template<typename Derived>
+const SparseView<Derived> MatrixBase<Derived>::sparseView(const Scalar& m_reference,
+                                                          const typename NumTraits<Scalar>::Real& m_epsilon) const
+{
+  return SparseView<Derived>(derived(), m_reference, m_epsilon);
+}
+
+} // end namespace Eigen
+
+#endif