The name `find' does not exist in the context of `GLib.ListStore'

Question

I'm totally clueless why this error is being thrown. The valadoc shows that this function exist. The append function also works. Here's the code to reproduce it:

class some_object : GLib.Object {
    public int val {get; construct;}
    public some_object (int val) {
        Object (
            val: val
        );
    }
}

class ExampleList : Gtk.ApplicationWindow {
    construct {
        var dummy = new some_object(0);
        var model = new GLib.ListStore (GLib.Type.from_instance (dummy));
        model.append (dummy);
        uint position;


        model.find (dummy, out position);

        //    ^^^^

    }
}

class MyApplication : Gtk.Application {
    public MyApplication () {
        Object (
            application_id: "com.example.listbox"
        );
    }
    public override void activate () {
        new ExampleList (). show_all ();
    }
}

public static int main (string[] args) {
    return new MyApplication (). run (args);
}

To compile I use:

valac --pkg=gtk+-3.0 so.vala

And the error I'm getting is:

so.vala:18.9-18.18: error: The name `find' does not exist in the context of `GLib.ListStore'
        model.find (dummy, out position);
        ^^^^^^^^^^
Compilation failed: 1 error(s), 0 warning(s)

Answer 1

From the reference document you link to:

[ Version ( since = "2.64" ) ]

This GIO version was only released this year: it's likely that you are using an older version that does not include this function.