CFD Online Discussion Forums - Write out labelListList cellCells()

Hello all,

I am attempting to write out cell center connectivity to a file. I started with the foamToFluent utility and modified it according to my needs. However, my C++ and research skills are rapidly running out.

From https://www.cfd-online.com/Forums/op...edge-cell.html and https://jibranhaider.com/blog/mesh-i...connectivities I know that I need to access cellCells() and that it is a labelListList. My understanding is that this is a list of lists, which makes sense. The section of my code indented to write this information to file is below.

When compiling I am getting an error relating to, I believe, a mismatch in expected data type for the ```edge_list << neighbour[celli] ``` command. This error message is shown below.

I think my lack of understanding of labelListList is the root cause of this error. And after some exhaustive searching I am not sure of where to go from here. I would greatly appreciate help in understanding what I am doing wrong. I can easily imagine that naively calling cellCells()[celli] is not how I should go about this, but without knowing the structure of cellCells I am left to guess.

Any help is greatly appreciated, thank you,

- Sam

Compiler error message:

Code:

error: no match for ‘operator<<’ (operand types are ‘std::basic_ostream<char>’ and ‘const Foam::List<int>’)

         edge_list << " " << neighbour[celli];

Code:

    // Open a file for the edges

    std::ofstream edge_list

    (

        time().rootPath()

      / time().caseName()

      / "graph"

      / "edges.txt"

    );



    Info<< "Writing edges.txt" << endl;



    // Writing cells based on neighbors

    const labelListList neighbour = this->mesh.cellCells();



    // Writing number of cells

    edge_list

        << "("

        << nCells() << ")" << std::endl;

    edge_list << "(";

 

    forAll(neighbour, celli)

    {

        edge_list << " " << neighbour[celli];

        edge_list << "\n";

    }



    edge_list << ")" << std::endl;