Why is the following not allowed in a class declaration?

    property Increment: extended read FIncrement write SetIncrement default 1.0;

yet this is...

    property Increment: integer read FIncrement write SetIncrement default 1;

What would be the major obstacle between Extended and Integer types? How can I overcome this issue?

Regards,
- Graeme -

_______________________________________________
fpGUI - a cross-platform Free Pascal GUI toolkit
http://opensoft.homeip.net/fpgui/

Graeme Geldenhuys wrote

Why is the following not allowed in a class declaration? property Increment: extended read FIncrement write SetIncrement default 1.0;

Because default values are stored in a 32 bit location inside the compiler. I have no idea what the reason for this is, how Delphi does this and what it allows, whether this not only a matter of the compiler but also of the rtti, ...

How can I overcome this issue?

You cannot.

Jonas

Using stored instead of default?

FPC is 100% Delphi compatible as FPC. Default values for sets are also only allowed for sets that fit in 32-bits. We can change this, but that would require quite some work in the RTTI structures.

Michael.

If this area is typed, and the size is 64 for the 64 bits compiler, you could store a pextended instead of the value itself. Just a thought.

Michael Van Canneyt wrote

FPC is 100% Delphi compatible as FPC. Default values for sets are also only allowed for sets that fit in 32-bits. We can change this, but that would require quite some work in the RTTI structures.

So do you think this will change in 64bit Delphi and then in 64bit FPC? RTTI structures also supporting 64bit values? It would make sense (to me at least). :-)

I just thought it odd that I couldn't use a simple type (I consider Extended a simple type, like Integer and String) in a property with a default value.

Regards,
- Graeme -

_______________________________________________
fpGUI - a cross-platform Free Pascal GUI toolkit
http://opensoft.homeip.net/fpgui/

In our previous episode, Graeme Geldenhuys said:

Integer is still 32-bit on x86_64 ?

No, only ordinal types... Strings are also not supported.

Michael.

Empty String it is a default value.

What if increase to size of default value to int64 so we can add default value to Currency/Double properties, and that make my exported XML more small, and it is still compatible with Delphi.