class operator, AND/OR/XOR question

[A.M. Hoornweg 144]

Hello all,

 

I see that Delphi supports both bitwise and logical versions of and/or/xor operator overloading, but I'm not 100% sure about the difference between the two concepts. 

Assume I have a certain record type, and that I want to implement "AND", "OR" and "XOR" operators, each resulting in some kind of merge of the original input records.  The syntax I would like to use in my code would simply be "A:=(B OR C);"   

 

Do I need to implement BitWiseOr etc or LogicalOr, and if I implement both, how does Delphi decide which of the two is going to be used?

 

 

[David Heffernan 2345]

It's explained in the documentation. Which should always be the first port of call when contemplating such an issue.

 

Its here:

 

http://docwiki.embarcadero.com/RADStudio/en/Operator_Overloading_(Delphi)

 

I could highlight the key text for you, but I'm sure you are more than capable of finding it. 

[Uwe Raabe 2057]

From the Docwiki: 
 

Quote

• For a logical operator and a bitwise operator using the same symbol, the logical operator is used only when the operands are booleans. Since the type of record for this record operator is not a boolean, a logical operator will only be used when the other operand is a boolean.

 

Oops: too late

Edited February 22, 2021 by Uwe Raabe

[A.M. Hoornweg 144]

I did consult the wiki but somehow managed to skip this line of text ten times. It must be monday morning ....

 

Thanks for pointing it out!