Cardinal: what changed

Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.

Title: Cardinal

New		Line
1	+	Cardinal is an integer type defined as an alias for [[DWord]] under a 32-bit platform. Like the DWord (double word) type it's 32 bits and interpreted as an unsigned integer. Its minimal value is 0x0000000 and its maximal value 0xFFFFFFFF (4,294,967,295).
2	+
3	+	On x86 systems Cardinal type is often used to hold a memory address, like a pointer:
4	+
5	+	``` pascal
6	+	var
7	+	anAddress: Cardinal;
8	+	anObject: TObject;
9	+	begin
10	+	anAddress := Cardinal(Self);
11	+	with TObject(anAddress) do
12	+	begin
13	+	// anAddress is casted as a TObject.
14	+	end;
15	+	end;
16	+	```
17	+
18	+	However, because of 32 and 64 bit little endian systems, using the Cardinal type is *not recommended* anymore for memory/pointer operations/arithmetic. It's recommended to use NativeInt or NativeUInt types instead. These types will match the width of the CPU registers which can be used to encode a memory address and so will always be the right size. For example under a 64b-bit OS, a NativeUInt will be like a UInt64 or a QuadWord and under a 32-bit OS, a NativeUInt will be like a DWord or a Cardinal.
19	+
20	+	---
21	+	From the Free Pascal wiki, page "Cardinal", as it stood on 2020-11-24 after a change by Arent, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).