record operator initialize in a class, when does it get called?

[jamie]

Lets say we have this

Code: Pascal  [Select][+][-]

1. Type
2. TMyRecord = Record
3.  X,Y:Integer;
4. Class Operator initialize(var O:TmyRecord);
5. end;
6.  

And I put it in a class, lets say in the public area of TFORM1.

Code: Pascal  [Select][+][-]

1. Tform1 = Class(...)
2.  
3. Public
4.    Myrecord:TMyRecord;
5. End;
6.  
7.  

While I am in the constructor of Form1, I can see that MYRecord has gotten initiaiized.

Where at what point during the creation of TFORM1 or any class that houses records like this, does the Initialize code get called ?

[Khrys]

As a stack trace:

Code: Pascal  [Select][+][-]

1. #0  class operator TMyRecord.Initialize(var O: TMyRecord);
2. #1  class function TObject.InitInstance(Instance: Pointer): TObject;
3. #2  class function TObject.NewInstance(): TObject;
4. #3  constructor TForm1.Create();

In other words, it's done right after the instance's memory is allocated (and zeroed) in the preamble of the constructor. If you take a look at the source of  TObject.InitInstance  you'll see comments and some code related to management operators.

[jamie]

Thank you for that information, that is exactly what I was looking for.

I don't recall seeing that in the DOCs?

[Thaddy]

Well, https://www.freepascal.org/docs-html/3.2.2/rtl/system/tobject.newinstance.html.
Anything after that gets called later.
( The doc is not totally correct: overriding NewInstance allows for allocating a class on the stack too. Only use if you know what you are doing. )

[PascalDragon]

I don't recall seeing that in the DOCs?

Well, it should probably be mentioned here... Best file a bug report against the documentation then.