Help needed with operator overloading with advanced records
lazarus / 62-General

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ad1mt · 2024-02-09 18:43

I'm having trouble with operator overloading with advanced records.
I've read the documentation and the "Object Pascal Handbook" by Marco
Cantu (although its possible I may not have understood it correctly 
)

I've been able to get it working in {MODE DELPHI} but not in {MODE
OBJFPC} with {$MODESWITCH ADVANCEDRECORDS} where I'm getting errors
like "Impossible operator overload".

Here is an example program, that shows the problem:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i {$MODE
OBJFPC}{$MODESWITCH ADVANCEDRECORDS}// {$MODE DELPHI} program
test_extended_record_2;typeT_R = record        R_Val:int64;     
public        class operator :=(const v:int64):T_R;        class
operator add(const v1,v2:T_R):T_R;      end;varv1,v2,v3:T_R; class
operator T_R.:=(const v:int64):T_R;beginResult.R_Val:= v;end; class
operator T_R.add(const v1,v2:T_R):T_R;beginResult.R_Val:= (v1.R_Val +
v2.R_Val);end; beginv1:= 1;v2:= 2;v3:= (v1 + v2);writeln('v3 =
',v3.R_Val);end.My main question is: should it be possible to get this
program working in {MODE OBJFPC} with {$MODESWITCH ADVANCEDRECORDS} ?
And if it is possible, how?
Thanks.
PS:- I have got other questions, but I will ask them one-at-a-time.

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Warfley · 2024-02-09 18:55

I think that operators are named differently in Mode Delphi and in
Mode ObjFPC. In Delphi its names (Explicit, Implicit, Add, Subtract,
etc.) and in Mode ObjFpc sind es Symbole (:=, +, -).

So either do this in Mode Delphi:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i        
class operator Implicit(const v:int64):T_R;        class operator
add(const v1,v2:T_R):T_R;Or this in mode ObjFPC:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i        
class operator :=(const v:int64):T_R;        class operator +(const
v1,v2:T_R):T_R;
But don't mix

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Thaddy · 2024-02-09 19:31

Is correct.

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ad1mt · 2024-02-10 10:35

Quote from: Warfley on February 09, 2024, 07:55:07 pmI think that
operators are named differently in Mode Delphi and in Mode ObjFPC. In
Delphi its names (Explicit, Implicit, Add, Subtract, etc.) and in Mode
ObjFpc sind es Symbole (:=, +, -).
But don't mix
I've got it working now.
Thanks.

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Thaddy · 2024-02-10 11:02

We had about the same question late last year...

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ad1mt · 2024-02-10 11:42

Quote from: Thaddy on February 10, 2024, 12:02:37 pmWe had about the
same question late last year...
That was probably me. Sorry... I got confused. I'm getting old now,
and my brain does not work as well as it used to when I was younger.
I now do programming as a hobby, because I'm hoping it will help keep
my brain healthy as I get older...