Structure as a procedure parameter

[SeaWolf]

Hello,

Here is a simplified example to show the problem I'm having :

Code: Select all

Structure Config
    Colour$
EndStructure

Procedure showSettings(*settings.Config)
    
    MessageRequester("", *settings\Colour$)
    
EndProcedure

Procedure updateSettings(*settings.Config)
    
    *settings\Colour$ = "blue"
    showSettings(@settings)
    
EndProcedure

settings.Config
updateSettings(@settings)

So, showSettings is called from updateSettings, but the MessageRequester shows that *settings\Colour$ is empty...

What is wrong ? Probably something about the pointers, I'm not sure I understand everything about that

[Shardik]

In procedure updateSettings() simply change

Code: Select all

showSettings(@settings)

to

Code: Select all

showSettings(*settings)

because settings and *settings are different variables. An EnableExplicit at the beginning would have informed you about that...

[SeaWolf]

Thank you Shardik, I don't know how I missed that! Now it works nicely

[Yuri_D]

Hi!

Could anybody explain please the difference between Proc( @structure) and Proc( structure) calls for:

Code: Select all

Procedure.i Proc( *struct.structure)

Both are working... Which one is correct?

BRG Yury

[StarBootics]

Hi!

Could anybody explain please the difference between Proc( @structure) and Proc( structure) calls for:

Code: Select all

Procedure.i Proc( *struct.structure)

Both are working... Which one is correct?

BRG Yury

This is the good way :

Code: Select all

Structure Config
		Colour$
EndStructure

Procedure showSettings(*settings.Config)
		
		MessageRequester("", *settings\Colour$)
		
EndProcedure

Procedure updateSettings(*settings.Config)
		
		*settings\Colour$ = "blue"
		showSettings(*settings)
		
EndProcedure

settings.Config
updateSettings(settings)

[Demivec]

Could anybody explain please the difference between Proc( @structure) and Proc( structure) calls for:

Code: Select all

Procedure.i Proc( *struct.structure)

Both are working... Which one is correct?

They are both the same.

It is true that a structure used as a parameter currently and in the past versions of PureBasic, will always send its address and not its contents but good code etiquette would probably say that you should explicitly show that you are using the address of the structure (@structure) itself to avoid confusion.

To the contrary I personally prefer to usually leave off the '@' operator in this case.

[Yuri_D]

Hi!

Thank you for the explanation!

BRG
Yury