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Can an object pass a handle to itself?

Asked by Bruce Elliott on 23 Aug 2019
Latest activity Edited by Matt J
on 23 Aug 2019
Can an object of a handle class pass its own handle to a function, so that the function has access to certain properties of the object? I believe this would be similar to use of the 'this' pointer in C++.
Here's what I'm trying to do, in case there's a better way to accomplish it:
I have class A, instances of which will create child objects that are instances of another class B. Objects of class B will only ever exist as children of class A objects, and their behavior will depend on the current values of some their parent's properties. Thus I'd like them to have the handle to their parent as one of their properties.
Thus, I'd like the parent to be able either to set the child's property directly or to pass a handle to the class B constructor.
The only easy (but tedious) alternative I see is to have the parent explicitly pass the current values of any required properties to the methods of the child when it calls them.
Suggestions?
Thanks.

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1 Answer

Answer by Matt J
on 23 Aug 2019
Edited by Matt J
on 23 Aug 2019
 Accepted Answer

Yes, you can pass an instance of A to the constructor of each child B. And, if A is a handle class, this will provide each child with pointer-like access to the property values of A.

  2 Comments

Right after I submitted this question, I realized that the 'obj' variable that I routinely use in my class methods is essentially a "this" pointer, isn't it? I should be able to pass that to the constructor of my child object, right?
Matt J
on 23 Aug 2019
I should be able to pass that to the constructor of my child object, right?
Yes.
Also, if the properties of A are read-only, you don't even need to make A a handle class. It can be a value class instead and still be stored by all of its children.

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