Created attachment 365063 [details] [review]
0002-codegen-don-t-wrap-generic-GDestroyNotify.patch

As reference for the reason to create null-safe destroy-functions in this situation: https://git.gnome.org/browse/vala/commit/?id=f06c7c67cc1c2f626b06a676583f3716d3c155ae

Let's be specific - the example is attempting to create a new GenericArray in the constructor for the object. I think a work around is probably:

class Test<T> {
    public GenericArray<T> inner = new GenericArray<T> ();

    public Test () {
        //inner = new GenericArray<T> ();
    }
}

void main () {
    var test = new Test<string> ();
}

but it doesn't solve the bug. At the level of Vala syntax this is a similar problem to https://bugzilla.gnome.org/show_bug.cgi?id=791060

(In reply to Al Thomas from comment #3)
> Let's be specific - the example is attempting to create a new GenericArray
> in the constructor for the object. I think a work around is probably:
> 
> class Test<T> {
>     public GenericArray<T> inner = new GenericArray<T> ();
> 
>     public Test () {
>         //inner = new GenericArray<T> ();
>     }
> }
> 
> void main () {
>     var test = new Test<string> ();
> }
> 
> but it doesn't solve the bug. At the level of Vala syntax this is a similar
> problem to https://bugzilla.gnome.org/show_bug.cgi?id=791060

If the programmer doesn't want to construct a generic class, may be because she/he doesn't want to expose Vala generic API, you can extend above class as:

public class Bar : Test<int> {}

So your users will have a non generic int implemented class.

(In reply to Daniel Espinosa from comment #4)
> If the programmer doesn't want to construct a generic class, may be because
> she/he doesn't want to expose Vala generic API, you can extend above class
> as:
> 
> public class Bar : Test<int> {}

While that may be a useful programming tip, I'm not sure it relates to this bug. I'm still getting the error reported originally when I compile:

class Test<T> {
    public GenericArray<T> inner;

    public Test () {
        inner = new GenericArray<T> ();
    }
}

class Bar : Test<string> {}

void main () {
    var test = new Bar ();
}

However T is available in the scope of the class:

class Test<T> {
    public GenericArray<T> inner;

    public Test () {
        print (@"$(typeof(T).name())\n");
        //inner = new GenericArray<T> ();
    }

    public void print_type () {
        print (@"$(typeof(T).name())\n");
    }
}

void main () {
    var test = new Test<string> ();
    test.print_type ();
}

produces:

gchararray
gchararray

*** Bug 791060 has been marked as a duplicate of this bug. ***

Created attachment 365165 [details] [review]
codegen: Don't create null-safe destroy-wrapper for GenericType

Attachment 365165 [details] pushed as ac0dbad - codegen: Don't create null-safe destroy-wrapper for GenericType