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

[vuott at tutanota.com]

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)
>>>>
>>>> ----[ >>>> http://gambaswiki.org/wiki/doc/netiquette>>>>  ]----
>>>>
>>>
>>> ----[ >>> http://gambaswiki.org/wiki/doc/netiquette>>>  ]----
>>>
>>
>> ----[ >> http://gambaswiki.org/wiki/doc/netiquette>>  ]----
>>

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