Added checking for negative number of elements. Debuggin prints included

   TNL_ASSERT_GT( this->getColumns(), 0, "cannot set row lengths of an empty matrix" );

   TNL_ASSERT_EQ( this->getRows(), rowLengths.getSize(), "wrong size of the rowLengths vector" );

   this->rowLengths = this->maxRowLength = max( rowLengths );

   this->rowLengths = this->maxRowLength = rowLengths.max();

   std::cout << "  this->rowLengths = " << this->rowLengths << std::endl;

   allocateElements();

}

   this->rowLengths = matrix.rowLengths;

   this->setDimensions( matrix.getRows(), matrix.getColumns() );

   std::cout << "DIMENSIONS set; after setDimensions in operator= cross-device" << std::endl;

   const int blockSize = 32;

   const int blocks = roundUpDivision( this->getRows(), blockSize );

          typename Index >

void Ellpack< Real, Device, Index >::allocateElements()

{

    // The allocation process isn't limited by RAM with ELL, but rather the size of the values and indexes arrays. Bcs ELL will store rows*maxRowLength elements in one array.

    // The PROBLEM arises when we try to store the entire matrix into one array, which is what ELL essentially does in this case.

   std::cout << "  this->alignedRows = " << this->alignedRows << "\t this->rowLengths = " << this->rowLengths << std::endl;

   // HOW? Will we have to do this with every format? How to make this global?

   IndexType numMtxElmnts = this->alignedRows * this->rowLengths;

   // CORRECT? Can the overflown value pass this assert?

   TNL_ASSERT_TRUE( this->alignedRows != 0 && numMtxElmnts / this->alignedRows == this->rowLengths, "Ellpack cannot store this matrix. The number of matrix elements has overflown the value that IndexType is capable of storing" );

   // ORIGINAL from: https://stackoverflow.com/questions/1815367/catch-and-compute-overflow-during-multiplication-of-two-large-integers

//   if (this->alignedRows != 0 && numMtxElmnts / this->alignedRows != this->rowLengths) {

//       TNL_ASSERT_FALSE( this->alignedRows != 0 && numMtxElmnts / this->alignedRows != this->rowLengths, "Ellpack cannot store this matrix. The number of matrix elements has overflown the value that IndexType is capable of storing" );

//   }

//   else

//   {

//       Sparse< Real, Device, Index >::allocateMatrixElements( this->alignedRows * this->rowLengths );

//   }

   Sparse< Real, Device, Index >::allocateMatrixElements( this->alignedRows * this->rowLengths );

}