[fpc-devel] indexed property with default value for param?

Martin Friebe fpc at mfriebe.de
Thu Jun 11 21:10:22 CEST 2009

Daniƫl Mantione wrote:
> Op Thu, 11 Jun 2009, schreef Michael Van Canneyt:
>> On Thu, 11 Jun 2009, Jonas Maebe wrote:
>> I would think it is a natural extension of procedural overloading ?
> It's not that simple. Properties can be both hidden variable access as 
> well as procedure access. Variable overloading is not allowed, because 
> it causes a lot of issues, i.e.:
> var a:word;
>     a:char;
> begin
>   a:=1;
>   a:='!';
>   writeln(a); {what does this mean??}
> end;
> Property overloading gets you the same issues, i.e. in the example 
> above you could replace both variables with properties and answer the 
> same question.
> Considering this, I do not think it can considered a logical extension 
> of procedure overloading.

Good point.

However the example above (even so you use the setter [assign to the 
property] instead of reading), is the same as overloading *functions* by 
You can not overload functions by result; still you can overload them by 

So consistency of overloading functions is *not* defined by being able 
to use every bit of information on the function for the overloading; but 
only selected (the parameters passed to the function).

On properties this question was about the index given to a property 
(number and type of indexes). I do agree, it can not be about the type 
of the property itself.


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