[Vala] Using Gee.ArrayList and Gee.Queue

[Osmo Antero <osmoma gmail com>]

Hello,
I would like to use Vala for my next project, so I started to learn
some basic features.
Please see the example code below.

Question 1:
When compiling the program, it outputs the following warning:

$ valac --pkg gee-1.0  test.vala
/home/moma/V/list1.vala.c: In function ‘main_test’:
/home/moma/V/list1.vala.c:105:2: warning: passing argument 1 of
‘gee_abstract_collection_get_size’ from incompatible pointer type
[enabled by default]
/usr/include/gee-1.0/gee.h:755:6: note: expected ‘struct
GeeAbstractCollection *’ but argument is of type ‘struct GeeCollection
*’

It is caused by this statement:
stdout.printf("Size of list1:%u\n", list1.size);

But this statement (on list2.size) is perfectly OK.
stdout.printf("Size of list2:%u\n", list2.size);

So which of these two declarations is more correct?
  public ArrayList<int> list1 = new Gee.ArrayList<int>();
  or
  public Gee.List<int> list2 = new Gee.ArrayList<int>();

Please see the example code below.

Compile it with:
$ valac --pkg gee-1.0 test.vala

And run:
./test

Should I use GLib.List<x> instead of Gee.ArrayList<x> consequently?
------------------------

Question 2:
Why does this gee.Queue declaration fails?

Gee.Queue<int> queue = new Gee.Queue<int>();

test.vala:198.28-198.47: error: `Gee.Queue' is not a class, struct, or
error code
        Gee.Queue<int> queue = new Gee.Queue<int>();
                           ^^^^^^^^^^^^^^^^^^^^

// --------------------------------------
// Example code (test.vala):
// --------------------------------------
using GLib, Gee;

public class Main {
    public ArrayList<int> list1 = new Gee.ArrayList<int>();

    public Gee.List<int> list2 = new Gee.ArrayList<int>();

    public void test() {
        for (var i = 0; i < 10; i++) {
            list1.add(i);
        }
        stdout.printf("Size of list1:%u\n", list1.size);


      for (var i = 0; i < 10; i++) {
            list2.add(i);
        }
        stdout.printf("Size of list2:%u\n", list2.size);

    }

    public static int main (string[] args) {
        var t = new Main();
        t.test();
        return 0;
    }
}
// --------------------------------------

My system is:
$ cat /etc/issue
Ubuntu 12.04 LTS \n \l

Version of Vala is:
$ valac --version
Vala 0.17.0

Kindly
Osmo
http://www.futuredesktop.org
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