Function csr_sort_indices

dependence/eigen-3.4.0/bench/sparse_setter.cpp:351–375

template<class I, class T>
void csr_sort_indices(const I n_row,
                      const I Ap[],
                            I Aj[],
                            T Ax[])
{
    std::vector< std::pair<I,T> > temp;

    for(I i = 0; i < n_row; i++){
        I row_start = Ap[i];
        I row_end   = Ap[i+1];

        temp.clear();

        for(I jj = row_start; jj < row_end; jj++){
            temp.push_back(std::make_pair(Aj[jj],Ax[jj]));
        }

        std::sort(temp.begin(),temp.end(),kv_pair_less<I,T>);

        for(I jj = row_start, n = 0; jj < row_end; jj++, n++){
            Aj[jj] = temp[n].first;
            Ax[jj] = temp[n].second;
        }
    }
}

template <class I, class T>
void csr_sum_duplicates(const I n_row,