On Friday, November 22, 2013 11:21:35 Mf_Gh wrote:
> hi, i started to play a round with D and try to do something like:
>
> class A{
> string a = "alias A";
> alias a this;
> }
>
> class B:A{
> string b = "alias B";
> alias b this;
> }
>
>
> void main() {
> A b = new B();
> writeln(b); //outputs alias A
> }
>
> i thought the output would be "alias B". why isn't the alias
> taken from the runtimetype?
Because there's no virtual function involved. There's nothing virtal about
either a or b. They're just variables. You'd need to alias to a virtual
function if you wanted polymorphic behavior. e.g. something like
class A{
string a = "alias A";
string get() { return a; }
alias get this;
}
class B:A{
string b = "alias B";
override string get() { return b; }
alias get this;
}
void main() {
A b = new B();
writeln(b); //outputs alias A
}
- Jonathan M Davis
