clang++ -std=c++11 -Wall -g -I/usr/include/eigen3 ellpack.cpp -o ellpack
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:61:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:220:29: error: 
      no viable overloaded '='
          *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __secondChild));
          ~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:335:9: note: 
      in instantiation of function template specialization
      'std::__adjust_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, Eigen::Triplet<double, int>, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at
      ellpack.cpp:20:15)> >' requested here
          std::__adjust_heap(__first, __parent, __len, _GLIBCXX_MOVE(__value),
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1669:12: note: 
      in instantiation of function template specialization
      'std::__make_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__make_heap(__first, __middle, __comp);
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1930:12: note: 
      in instantiation of function template specialization
      'std::__heap_select<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__heap_select(__first, __middle, __last, __comp);
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1945:13: note: 
      in instantiation of function template specialization
      'std::__partial_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
              std::__partial_sort(__first, __last, __last, __comp);
                   ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1965:9: note: 
      in instantiation of function template specialization
      'std::__introsort_loop<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__introsort_loop(__first, __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:61:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:226:29: error: 
      no viable overloaded '='
          *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first
          ~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:61:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:131:29: error: 
      no viable overloaded '='
          *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __parent));
          ~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:230:12: note: 
      in instantiation of function template specialization
      'std::__push_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, Eigen::Triplet<double, int>, __gnu_cxx::__ops::_Iter_comp_val<(lambda at
      ellpack.cpp:20:15)> >' requested here
      std::__push_heap(__first, __holeIndex, __topIndex, 
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:335:9: note: 
      in instantiation of function template specialization
      'std::__adjust_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, Eigen::Triplet<double, int>, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at
      ellpack.cpp:20:15)> >' requested here
          std::__adjust_heap(__first, __parent, __len, _GLIBCXX_MOVE(__value),
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1669:12: note: 
      in instantiation of function template specialization
      'std::__make_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__make_heap(__first, __middle, __comp);
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1930:12: note: 
      in instantiation of function template specialization
      'std::__heap_select<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__heap_select(__first, __middle, __last, __comp);
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1945:13: note: 
      in instantiation of function template specialization
      'std::__partial_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
              std::__partial_sort(__first, __last, __last, __comp);
                   ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1965:9: note: 
      in instantiation of function template specialization
      'std::__introsort_loop<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__introsort_loop(__first, __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:61:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:135:32: error: 
      no viable overloaded '='
      *(__first + __holeIndex) = _GLIBCXX_MOVE(__value);
      ~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:61:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:246:17: error: 
      no viable overloaded '='
      *__result = _GLIBCXX_MOVE(*__first);
      ~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1672:9: note: 
      in instantiation of function template specialization
      'std::__pop_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__pop_heap(__first, __middle, __i, __comp);
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1930:12: note: 
      in instantiation of function template specialization
      'std::__heap_select<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__heap_select(__first, __middle, __last, __comp);
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1945:13: note: 
      in instantiation of function template specialization
      'std::__partial_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
              std::__partial_sort(__first, __last, __last, __comp);
                   ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1965:9: note: 
      in instantiation of function template specialization
      'std::__introsort_loop<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__introsort_loop(__first, __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:61:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:247:7: error: 
      no matching function for call to '__adjust_heap'
      std::__adjust_heap(__first, _DistanceType(0),
      ^~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:209:5: note: 
      candidate template ignored: substitution failure [with _RandomAccessIterator =
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      _Distance = long, _Tp = Eigen::Triplet<double, int>, _Compare =
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)>]
    __adjust_heap(_RandomAccessIterator __first, _Distance __holeIndex,
    ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:400:4: error: 
      no matching function for call to '__pop_heap'
          std::__pop_heap(__first, __last, __last, __comp);
          ^~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1931:12: note: 
      in instantiation of function template specialization
      'std::__sort_heap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort_heap(__first, __middle, __comp);
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1945:13: note: 
      in instantiation of function template specialization
      'std::__partial_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
              std::__partial_sort(__first, __last, __last, __comp);
                   ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1965:9: note: 
      in instantiation of function template specialization
      'std::__introsort_loop<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__introsort_loop(__first, __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_heap.h:237:5: note: 
      candidate template ignored: substitution failure [with _RandomAccessIterator =
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      _Compare = __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)>]
    __pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last,
    ^
In file included from ellpack.cpp:1:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/iostream:39:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/ostream:38:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/ios:40:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/char_traits.h:39:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algobase.h:148:7: error: 
      no matching function for call to 'swap'
      swap(*__a, *__b);
      ^~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:84:11: note: 
      in instantiation of function template specialization
      'std::iter_swap<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > > >'
      requested here
            std::iter_swap(__result, __b);
                 ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1918:12: note: 
      in instantiation of function template specialization
      'std::__move_median_to_first<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int>
      *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > >
      >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__move_median_to_first(__first, __first + 1, __mid, __last - 1,
           ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1950:11: note: 
      in instantiation of function template specialization
      'std::__unguarded_partition_pivot<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double,
      int> *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int>
      > > >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
            std::__unguarded_partition_pivot(__first, __last, __comp);
                 ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1965:9: note: 
      in instantiation of function template specialization
      'std::__introsort_loop<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__introsort_loop(__first, __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/move.h:177:24: note: 
      candidate template ignored: disabled by 'enable_if' [with _Tp = const Eigen::Triplet<double,
      int>]
    typename enable_if<__and_<is_move_constructible<_Tp>,
                       ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/move.h:202:5: note: 
      candidate template ignored: could not match '_Tp [_Nm]' against 'const
      Eigen::Triplet<double, int>'
    swap(_Tp (&__a)[_Nm], _Tp (&__b)[_Nm])
    ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_pair.h:471:5: note: 
      candidate template ignored: could not match 'pair' against 'Triplet'
    swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
    ^
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1906:4: error: 
      no matching function for call to 'iter_swap'
          std::iter_swap(__first, __last);
          ^~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1920:19: note: 
      in instantiation of function template specialization
      'std::__unguarded_partition<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int>
      *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > >
      >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      return std::__unguarded_partition(__first + 1, __last, __first, __comp);
                  ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1950:11: note: 
      in instantiation of function template specialization
      'std::__unguarded_partition_pivot<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double,
      int> *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int>
      > > >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
            std::__unguarded_partition_pivot(__first, __last, __comp);
                 ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1965:9: note: 
      in instantiation of function template specialization
      'std::__introsort_loop<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      long, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__introsort_loop(__first, __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/algorithmfwd.h:336:5: note: 
      candidate template ignored: substitution failure [with _FIter1 =
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      _FIter2 = __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >]
    iter_swap(_FIter1, _FIter2);
    ^
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1849:17: error: 
      no viable overloaded '='
              *__first = _GLIBCXX_MOVE(__val);
              ~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1882:9: note: 
      in instantiation of function template specialization
      'std::__insertion_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1968:9: note: 
      in instantiation of function template specialization
      'std::__final_insertion_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int>
      *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > >
      >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__final_insertion_sort(__first, __last, __comp);
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:1:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/iostream:39:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/ostream:38:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/ios:40:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/char_traits.h:39:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algobase.h:548:18: error: 
      no viable overloaded '='
            *--__result = std::move(*--__last);
            ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algobase.h:588:45: note: 
      in instantiation of function template specialization 'std::__copy_move_backward<true, false,
      std::random_access_iterator_tag>::__copy_move_b<const Eigen::Triplet<double, int> *, const
      Eigen::Triplet<double, int> *>' requested here
                                       _Category>::__copy_move_b(__first,
                                                   ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algobase.h:597:24: note: 
      in instantiation of function template specialization 'std::__copy_move_backward_a<true,
      const Eigen::Triplet<double, int> *, const Eigen::Triplet<double, int> *>' requested here
      return _BI2(std::__copy_move_backward_a<_IsMove>
                       ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algobase.h:668:19: note: 
      in instantiation of function template specialization 'std::__copy_move_backward_a2<true,
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > > >'
      requested here
      return std::__copy_move_backward_a2<true>(std::__miter_base(__first),
                  ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1848:8: note: 
      in instantiation of function template specialization
      'std::move_backward<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > > >'
      requested here
              _GLIBCXX_MOVE_BACKWARD3(__first, __i, __i + 1);
              ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algobase.h:673:53: note: 
      expanded from macro '_GLIBCXX_MOVE_BACKWARD3'
#define _GLIBCXX_MOVE_BACKWARD3(_Tp, _Up, _Vp) std::move_backward(_Tp, _Up, _Vp)
                                                    ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1882:9: note: 
      in instantiation of function template specialization
      'std::__insertion_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1968:9: note: 
      in instantiation of function template specialization
      'std::__final_insertion_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int>
      *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > >
      >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__final_insertion_sort(__first, __last, __comp);
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1827:12: error: 
      no viable overloaded '='
          *__last = _GLIBCXX_MOVE(*__next);
          ~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1864:7: note: 
      in instantiation of function template specialization
      'std::__unguarded_linear_insert<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double,
      int> *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int>
      > > >, __gnu_cxx::__ops::_Val_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
        std::__unguarded_linear_insert(__i,
             ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1883:9: note: 
      in instantiation of function template specialization
      'std::__unguarded_insertion_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double,
      int> *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int>
      > > >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__unguarded_insertion_sort(__first + int(_S_threshold), __last,
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1968:9: note: 
      in instantiation of function template specialization
      'std::__final_insertion_sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int>
      *, std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > >
      >, __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
          std::__final_insertion_sort(__first, __last, __comp);
               ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:4739:12: note: 
      in instantiation of function template specialization
      'std::__sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      __gnu_cxx::__ops::_Iter_comp_iter<(lambda at ellpack.cpp:20:15)> >' requested here
      std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
           ^
ellpack.cpp:19:10: note: in instantiation of function template specialization
      'std::sort<__gnu_cxx::__normal_iterator<const Eigen::Triplet<double, int> *,
      std::vector<Eigen::Triplet<double, int>, std::allocator<Eigen::Triplet<double, int> > > >,
      (lambda at ellpack.cpp:20:15)>' requested here
    std::sort(triplets.begin(), triplets.end(),
         ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
In file included from ellpack.cpp:2:
In file included from /usr/include/eigen3/Eigen/Dense:1:
In file included from /usr/include/eigen3/Eigen/Core:269:
In file included from /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/algorithm:62:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/6.3.1/../../../../include/c++/6.3.1/bits/stl_algo.h:1831:15: error: 
      no viable overloaded '='
      *__last = _GLIBCXX_MOVE(__val);
      ~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit copy assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
class Triplet
      ^
/usr/include/eigen3/Eigen/src/SparseCore/SparseUtil.h:154:7: note: candidate function (the
      implicit move assignment operator) not viable: 'this' argument has type 'const
      Eigen::Triplet<double, int>', but method is not marked const
13 errors generated.
make: *** [Makefile:11: ellpack] Error 1