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How do you check if object o has base type B?
Feb 04, 2016
Enjoys Math
Feb 04, 2016
Rikki Cattermole
Feb 04, 2016
Gary Willoughby
February 04, 2016
Gravatar of Enjoys MathPosted by Enjoys MathReply
Enjoys Math
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Consider:

class C {

}

class B : C {

}

class A : B {

}

class D : C {

}

C[] objList;

how do we test if objLis[k] is of base type "B"?

Ie for [new A(), new B(), new D(), new C()] would give output [true, true, false, false].

?

Thank you! :D
February 04, 2016
Gravatar of Rikki CattermolePosted by Rikki Cattermole
in reply to Enjoys Math		Reply
Rikki Cattermole
Gravatar of Rikki Cattermole
Posted in reply to Enjoys Math


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T[] list;

foreach(v; list) {
	if (SpecialT v2 = cast(SpecialT)v) {
		writeln(v2);
	} else {
		writeln("err");
	}
}

That should work.
February 04, 2016
Gravatar of Gary WilloughbyPosted by Gary Willoughby
in reply to Enjoys Math		Reply
Gary Willoughby
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Posted in reply to Enjoys Math


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On Thursday, 4 February 2016 at 05:51:22 UTC, Enjoys Math wrote:
> Consider:
>
> class C {
>
> }
>
> class B : C {
>
> }
>
> class A : B {
>
> }
>
> class D : C {
>
> }
>
> C[] objList;
>
> how do we test if objLis[k] is of base type "B"?
>
> Ie for [new A(), new B(), new D(), new C()] would give output [true, true, false, false].
>
> ?
>
> Thank you! :D

if (cast(B)objLis[k])
{
    // It's an instance.
}