Global Structures

[jj555s]

I've been trying use use a Global Struct however I get this eeror message:

error C2236: unexpected 'struct' 'my_struct'


my code (MyStruct.h)

struct my_struct {
int box2;
} extern struct my_struct boxedit;

[horace1]

you forgot the ; after the } which terminates the struct

struct my_struct {
int box2;
};
extern struct my_struct boxedit;

[jj555s]

i think i did that actually and it gave me the same error

[Roonie]

struct my_struct {
int box2;
};
extern struct my_struct boxedit;

isnt that trying to declare my_struct twice? (or is this a C thing again?) i would say - though im just guessing - to try this:

struct my_struct {
int box2;
};
extern my_struct boxedit;

[jj555s]

o nevermind it works

[horace1]

struct my_struct {
int box2;
};
extern struct my_struct boxedit;

isnt that trying to declare my_struct twice? (or is this a C thing again?) i would say - though im just guessing - to try this:

struct my_struct {
int box2;
};
extern my_struct boxedit;

yes, its a C thing! your version is OK in C++ but not C

however, in C you can achieve a similar thing using typedef

typedef struct  {
int box2;
} my_struct;
extern my_struct boxedit;

[jj555s]

I'm not too sure how to work this

every instance i make, it assumes it as local

[jj555s]

VIT error LNK2001: unresolved external symbol "struct my_struct boxedit" (?boxedit@@3Umy _struct@@A)

[jj555s]

I'm trying to have 1.cpp and 2.cpp share the struct, for example int box; but I'm having issues with 2.cpp saying it's not defined before it being used?

[horace1]

I'm not too sure how to work this

every instance i make, it assumes it as local

not sure what the problem is, if you have a header file my_struct.h

struct my_struct {
int box2;
};
extern struct my_struct boxedit;

you need to define boxedit in one file, e.g. file1.c

#include "my_struct.h"

struct my_struct boxedit;  // definition

void setup()
{
    boxedit.box2=10;   // setup a value
}

and the use it elsewhere, e.g. file2.c

#include "my_struct.h"

int main()
{
    setup();
    printf("%d\n", boxedit.box2);
    system("pause");
}

you then need to compile and link the files, e.g.
g++ file1.c file2.c

[jj555s]

Is void setup an automatic function? I'm using MFC for this progream

[Roonie]

wait . . .

youre using MFC and C together? you said your files are named *.cpp, right? please help me out a little: what language are you writing in?

(and if you could post a little more code, that would be excellentemente hente)