unsafe fn post_constraints(_n: i32) -> *mut vec<*mut IntVar> {

    // Create constant

    let n: i32 = _n;

    // Create some variables

    let x: *mut vec<*mut IntVar> = create_vars(n, 0, n, false);

    // Post some constraints

    all_different_wrapper(x, ConLevel_CL_DEF);

    // Post some branchings

    branch_wrapper(x as _, VarBranch_VAR_INORDER, VarBranch_VAR_MIN_MIN);

    // Declare output variables (optional)

    output_vars_wrapper(x);

    // Declare symmetries (optional)

    var_sym_break_wrapper(x);

    // Return the variable

    x

}

pub unsafe extern "C" fn callback(x: *mut vec<*mut IntVar>) {

    print!("First output is: {}", get_idx(x, 0));

}

fn run_basic_problem() {

    let args: Vec<String> = std::env::args().collect();

    if args.len() != 2 {

        println!("Invalid number of arguments");

        return;

    }

    let n: i32 = args[1].parse().expect("Invalid input");

    unsafe {

        let x = post_constraints(n);

        // make new dummy problem

        let p = new_dummy_problem();

        // Call problem.addvars()

        p_addVars(p, x);

        // Call problem.setcallback()

        p_setcallback(p, Some(callback));

        // Commented out currently as trying to print causes the assertion of

        // isFixed() in IntVar::getVal() to fail.

        // p_print(p);

        // Pass test if no crash occurs

        assert!(true);

}