On 7/13/12 3:18 PM, Christophe Travert wrote:
Andrei Alexandrescu , dans le message (digitalmars.D:172280), a écrit :
For Fruit.Seed it's Fruit, for AppleSeed it's Apple. This makes sense
because the Apple, which AppleSeed sees is the same object, which
Fruit.Seed sees as it's base type Fruit.
That would mean AppleSeed has two outer fields: a Fruit and an Apple.
Only one. Apple. And when AppleSeed.super seed this Apple, it sees a
fruit.
AppleSeed a;
assert(is(typeof(a.outer) == Apple));
assert(is(typeof(a.super) == Seed));
assert(is(typeof(a.super.outer) == Fruit));
//but:
assert(a.outer is a.super.outer);
If you can't figure out how can a.outer and a.super.outer have two
different types, but be the same, think about covariant return.
Makes sense, thanks.
Andrei
