• Paolo Invernizzi (22/22) Sep 22 2011 charset=us-ascii
• travert phare.normalesup.org (Christophe) (11/41) Sep 23 2011 Since your Bar has am immutable member, you cannot assign a Bar

Paolo Invernizzi <arathorn fastwebnet.it> writes:

	charset=us-ascii

Hi all,=20

I've found nothing on bugzilla for that, what I'm missing? Or it's a =
bug? (DMD 2.055)

struct Bar {
    immutable int i;
    this(int j){ i =3D j; }
}

struct Foo {
    Bar bar;
}

void main(){
   =20
    auto b =3D Bar(1);
   =20
    auto f =3D Foo();
    f.bar =3D Bar(2); // Error: can only initialize const member bar =
inside constructor
   =20
}

Cheers,=20
Paolo Invernizzi

travert phare.normalesup.org (Christophe) writes:

Paolo Invernizzi , dans le message (digitalmars.D.learn:29680), a
 écrit :
 
 --Apple-Mail-7--919646864
 Content-Transfer-Encoding: quoted-printable
 Content-Type: text/plain;
 	charset=us-ascii
 
 Hi all,=20
 
 I've found nothing on bugzilla for that, what I'm missing? Or it's a =
 bug? (DMD 2.055)
 
 struct Bar {
     immutable int i;
     this(int j){ i =3D j; }
 }
 
 struct Foo {
     Bar bar;
 }
 
 void main(){
    =20
     auto b =3D Bar(1);
    =20
     auto f =3D Foo();
     f.bar =3D Bar(2); // Error: can only initialize const member bar =
 inside constructor
    =20
 }
 

Since your Bar has am immutable member, you cannot assign a Bar 
instance, which is what you do in the line where there is an error.

If you want to perform an assignment, Bar.i cannot be immutable. If you 
really want Bar.i to be immutable, Foo must hold a pointer to Bar, so 
you can change this pointer, or Bar can be a class instead of a struct 
(which means Foo does contain a pointer to Bar, but you don't have to
notice it).

-- 
Christophe Travert