I am trying to learn more about the usage of immutable. This is a little D2 program:


immutable class S {
    static int x;
    static this() {
        S.x = 10;
    }
}
void main() {}


The compiler outputs:
test.d(3): Error: function test2.S._staticCtor1 without 'this' cannot be const/immutable

Can you tell me what's wrong or how I can fix it?

Bye and thank you,
bearophile

On Mon, 08 Mar 2010 09:08:26 -0500, bearophile <bearophileHUGS@lycos.com> wrote:

> I am trying to learn more about the usage of immutable. This is a little D2 program:
>
>
> immutable class S {
>     static int x;
>     static this() {
>         S.x = 10;
>     }
> }
> void main() {}
>
>
> The compiler outputs:
> test.d(3): Error: function test2.S._staticCtor1 without 'this' cannot be const/immutable
>
> Can you tell me what's wrong or how I can fix it?

There was a discussion on D.learn in December of last lear that resulted in this bug being filed:

http://d.puremagic.com/issues/show_bug.cgi?id=3598

Note that even if static functions were allowed in immutable classes/structs, the static field members will still be tagged as immutable, so your example shouldn't compile.

-Steve