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

[Jussi Lahtinen]

I understand that, but knowing the name allows you to write a function that
gives you what you want.

Jussi

On Fri, Apr 7, 2023 at 1:15 AM vuott--- via User <
user at lists.gambas-basic.org> wrote:

> Hi Jussi,
> it seems to me that Brian G was *not* interested in knowing the *name*
> (label) of the Structure, but that the instance of the Structure was a "
> *Structure*" Object .
>
>
>
> 6 apr 2023, 23:39 da jussi.lahtinen at gmail.com:
>
> But if TypeOf() tells it is an object, then can't you get the structure
> name with Object.Type()?
>
> Jussi
>
> On Thu, Apr 6, 2023 at 9:33 AM Brian G <brian at westwoodsvcs.com> wrote:
>
> Yes but this does not differentiate a structure from a normal object
>
> --
> Thanks
> Brian G
>
> Wednesday, 05 April 2023, 02:22PM -07:00 from Jussi Lahtinen
> jussi.lahtinen at gmail.com:
>
> There is already TypeOf() function. And you can get the class with
> Object.Type().
>
> Jussi
>
> On Wed, Apr 5, 2023 at 7:05PM 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)
>
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