nested static methods in Fusion not properly translated within C++ code

[mittelmark]

Hi,

let's assume i have the following code:

public static class Test {
    public static List<bool>() IsNa (List<float> x) {
        List<bool>() b;
        for (int i = 0; i < x.Count; i++) {
            if (Math.IsNaN(x[i])) {
                b.Add(true);
            } else {
                b.Add(false);
            }
        }
        return(b);
    }
    public static List<int>() Which (List<bool> b) {
        List<int>() w ;
        for (int i = 0; i < b.Count; i++) {
            if (b[i] == true) {
                w.Add(i);
            }
        }
        return(w);
    }
    public static void Main (string[] args) {
        List<float>() x ;
        x.Add(0.2);
        x.Add(0.5);
        x.Add(0.9);
        x.Add(Math.NaN);
        x.Add(2.2);
        x.Add(Math.NaN);
        // workaround with two lines
        List<bool>() inas = Test.IsNa(x);
        List<int>() nas = Test.Which(inas);
        // Nesting does not work in C++ but in C, C#, D, Java, JavaScript, TypeScript and Python - Swift not tested
        List<int>() nas2 = Test.Which(Test.IsNa(x));
        for (int i = 0; i < nas.Count; i++) {
            Console.WriteLine($"On position {nas[i]} the numeric value is NA!");
        }
    }
}

The code works in all languages I tested: C, C#, D, Java, JavaScript, TypeScript and Python but not in C++. The nesting is not properly transpiled. I did the workaround with 2 variables. The translated C++ code code for the nas2 line looks like:

std::vector<int> nas2 = Test::which(&static_cast<const List &>(Test::isNa(&x)));

May be this can be fixed. Otherwise I never nest ;)
Should I do a issue item?

Best,
Detlef

[pfusik]

Thanks for reporting! The issue was for passing collection storage. Fixed in 5b61d29

BTW, you can simplify your code to:

    public static List<bool>() IsNa(List<float> x) {
        List<bool>() b;
        foreach (float f in x)
            b.Add(Math.IsNaN(f));
        return b;
    }
    public static List<int>() Which (List<bool> b) {
        List<int>() w;
        for (int i = 0; i < b.Count; i++) {
            if (b[i])
                w.Add(i);
        }
        return w;
    }

[mittelmark]

Thanks, that works just fine. Checked as well Swig now.

The if (b[i] == true) was a workaround as I had some problems with that if (b[i]) construct. But now all seems fine.

I will not wrap parts of glib with SWIG to continue with Lists within other languages targeted by SWIG. But that is another story ...