[Gambas-user] Answer to: "Way to tell if an object is a struct"

[Jussi Lahtinen]

There is already TypeOf() function. And you can get the class with
Object.Type().

Jussi

On Wed, Apr 5, 2023 at 7:05 PM vuott--- via User <
user at lists.gambas-basic.org> wrote:

> On this thread
>    https://lists.gambas-basic.org/pipermail/user/2023-March/078862.html
> Brian G asked, if it were possible to know if an Object is a Structure.
> In Gambas source file
>    /home/[USER]/gambasdevel/main/share/gambas.h
> the numbers of datatypes identifiers are listed.
> Therefore, by knowing which number a declared variable belongs to, it is
> possible to know its data type.
> I found a way to know, from the memory address of the variable it is
> necessary to go back 8 units. Deferencing the Pointer will give the
> identifier number of the data type of the variable, which consequently will
> have to be compared with the list above.
>
> This is my simply code:
>
> [code]
> Public Struct Struttura
>   b As Byte
>   c As Short
> End Struct
>
> Private id As Struct Struttura
>
>
> Public Sub Main()
>
> Dim p As Pointer
>
> p = VarPtr(id)
>
> Print "Gambas datatype identifier: "; Byte@(p - 8)
>
> End
> [/code]
>
> It should be noted that in the list of data-type identifier numbers, in
> particular, the data type Structure is NOT present.
> It will be located and reported by my code as an "Object" (number: 16)
>
> ----[ http://gambaswiki.org/wiki/doc/netiquette ]----
>
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