how to define a torch model as an input of a function in c++

Question

I'm loading a model in c++, which was trained in python. Now I want to write a function which tests the model with a random input but I can't define the model as an argument for the function. I've tried struct but it doesn't work.

void test(vector<struct comp*>& model){
    //pseudo input
    vector<torch::jit::IValue> inputs;
    inputs.push_back(torch::ones({1,3,224, 224}));

    at::Tensor output = model[0]->forward(inputs).toTensor();
    cout << output << endl;
}

int main(int argc, char *argv[]) {

    if (argc == 2){
        cout << argv[1] << endl;
        //model = load_model(argv[1]);
        torch::jit::script::Module module = torch::jit::load(argv[1]);

    }
    else {
        cerr << "no path of model is given" << endl;
    }
    // test
    vector<struct comp*> modul;
    modul.push_back(module);
    test(modul);
}

Answer 1

Edit: You need to put your module variable in scope!

Your basic type is torch::jit::script::Module so define a name for it:

using module_type = torch::jit::script::Module;

Then use that in your code, also use a const reference for read-only parameter:

void test(const vector<module_type>& model){
    //pseudo input
    vector<torch::jit::IValue> inputs;
    inputs.push_back(torch::ones({1,3,224, 224}));

    at::Tensor output = model[0]->forward(inputs).toTensor();
    cout << output << endl;
}

int main(int argc, char *argv[]) {

    if (argc == 2){
        cout << argv[1] << endl;            
    }
    else {
        cerr << "no path of model is given" << endl;
        return -1;
    }

    // test
    module_type module = torch::jit::load(argv[1]);;
    vector<module_type> modul;
    modul.push_back(module);
    test(modul);
}