why cant i access my struct?

haxxe

Hi, i got a struct like this:

    typedef struct name{
        static int v1;
        int v2;	
        int v3;	
        int v4;	
    } another_variable;

in the .cpp i want to access the static variable but the compiler says:
"undefined reference to MainWindow::name::v1"
i want to access it like this:

name Name;
Name.v1 = 0;

it seems like that i can get to the "normal" ints, but not the static one, why?

Devopia53

@haxxe

You are missing explicitly initialization for static member.

like this: int another_variable::v1 = 0;

haxxe

@Devopia53
in the .cpp or .h?
If I do it right before my function it says something like:

error: qualified-id in declaration before ‘=’ token

and i is it right, that i use the another variable and not the name?

EDIT: i guess i got it.
Not in an function, just above everything i had to write:

int MainWindow::another_variable::v1 = 0;

now it compiles, but is this right?

mrjj

Hi
Can i ask what you need that single static for ?

int MainWindow::another_variable::v1 = 0;
This is correct syntax for init a static class member. Yes
in .cpp , global scope.

now it compiles, but is this right?

Yes its correct with syntax but statics are not often used so
i do wonder what the goal of the design is :)

haxxe

got it to work, just got rid of the static.
actually, i only wanted to create this variable one time at all.

mrjj

@haxxe said in why cant i access my struct?:

Actually, i only wanted to create this variable one time at all.

For a complex object, that is expensive to construct a static might be the solution but
for an int, const might be better even it dont only create it only once but pr instance of the owning class.

haxxe

yes, but right now its working and im happy with it :D thanks for all your help.
Qt is awesome, as IDE, as Community, as everything.
its kinda complex to me because i'm really fresh to programming, but i already love it.

mrjj

@haxxe
Super
Yep I love Creator too. Very nice editor and Qt as GUI framework is the best i have tried.
Indeed, if you not used c++ super much, the full blown details when starting can be daunting but
you can always ask here. we also have a c++ section if not related to Qt as much.

haxxe

l also get problems because i work together with a friend on my projects, and hes just a full c gui, not c++ and this causes problems sometimes. i tried several things, but stick with qt now. its just amazing that i can develop an desktop programm and with 2 clicks it runs already on my pi.

mrjj

@haxxe
Yep, there is long way from c to c++ regarding program architecture.
But classes do offer a lot of benefits.