Find the heir.

[WebFreak001]

On Sunday, 29 March 2020 at 15:07:37 UTC, Simen Kjærås wrote:
> On Sunday, 29 March 2020 at 14:04:53 UTC, TodNaz wrote:
>> Hello!
>>>class A
>>>{
>>>    ...
>>>}
>>>
>>>class B : A
>>>{
>>>    ...
>>>}
>>>
>>>class C : A
>>>{
>>>    ...
>>>}
>>>
>>>A example1;
>>>B example2 = new B(...);
>>>A = example2;
>>>auto heir = A.whoheir(); ///
>>
>> The question in this code is: is it possible to track the 
>> class inheritor? Or is it beyond D?
>> Sorry if the question is fool ...
>
> The question is a bit unclear - what is whoheir expected to 
> return? This is one way that may or may not fulfill your 
> requirements:
>
> module foo;
> class A {
>     string whoheir() {
>         return typeid(this).name;
>     }
> }
> class B : A {}
> class C : A {}
>
> unittest {
>     A a = new B();
>     assert(a.whoheir == "foo.B");
>     a = new C();
>     assert(a.whoheir == "foo.C");
> }
>
> --
>   Simen

to extend on this: typeid(...) returns a TypeInfo so you can 
perform a bit of runtime reflection, see 
https://dlang.org/phobos/object.html#.TypeInfo

To check for exact matches if your class is B or C, you can also 
use
typeid(variable) == typeid(B)
if you don't want to compare arbitrary strings. (better code 
style)

There are also libraries to help you do this sort of runtime 
reflection like witchcraft: 
https://code.dlang.org/packages/witchcraft

or a more current hunt fork, though I don't know yet what it 
changes: https://github.com/huntlabs/hunt-reflection