void* problem

I'm building a data grid control.

It's struct which is I set in SetWindowLong is the MITH32GRIDSTRUCT struct.

Code:

---

typedef struct{
  LPSTR lpText,lpValue;
  int id,iIndex,iNumObjects,iType,iValue;
  bool bState,bValue;
  void *objects;
  RECT rc;
 }GRIDOBJECT;
 
 typedef struct{
  GRIDOBJECT*stems;
  int iNumStems;
  bool bInit,bSet;
  HICON *icons;
 }MITH32GRIDSTRUCT,*lpMITH32GRIDSTRUCT;

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Anyway, as you can see the grid has an array of GRIDOBJECT (stems)..

I needed GRIDOBJECT to have an array of GRIDOBJECT, I could have made an identical struct but I thought I could use void* for it.. However now when it comes time to size the rects of each item in the grid (which I handle on WM_SIZE) I have a problem..

Code:

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    void size( GRIDOBJECT* object, int index, int type, RECT rc ){
           
            int j = index;
            while( j < (GRIDOBJECT)object->objects[index]->iNumObjects ){
             
              if( object->objects[j]->iType == 1 ){
                    object->objects[j]->rc.top = rc.bottom;
                    object->objects[j]->rc.bottom += rc.bottom-rc.top;
                    object->objects[j]->rc.left = rc.left;
                    object->objects[j]->rc.right = rc.right;
              }else{
                    object->objects[j]->rc.top = rc.bottom;
                    object->objects[j]->rc.bottom = rc.bottom-rc.top;
                    object->objects[j]->rc.left = rc.left;
                    object->objects[j]->rc.right = rc.right;
                    size(&object->objects[j], 0, 1, rc);
              }
              j++;
            }
           
    }

---

I call that for each of the GRIDOBJECT*stems in the MITH32GRIDSTRUCT struct. But I get an error because object->objects[] is a void* ...

Quote:

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void* is not a pointer-to-object type

---

What should I do?

You can't index a void pointer directly because it is unknown to the compiler what the heck it's pointing to. That's what it's crying about.
Try casting it: ((LPRECT*)object->objects)[j]->rc...

I've tried casting all sorts of types but I still get the error (MingW).

This is the first line which gets the error --

Code:

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while( j < object->objects[index]->iNumObjects ){

---

I've tried -

Code:

---

while( j < (int)object->objects[index]->iNumObjects ){

---

But to no avail.

There are a number of different ways to go about this. Using the code you have, modify your 'size' function as follows ( create a temporary pointer to objects member of GRIDOBJECT and use that to access RECT member):

Code:

---

void size( GRIDOBJECT* object, int index, int type, RECT rc ){
     
  GRIDOBJECT *go=(GRIDOBJECT*)object->objects;
  int j = index;

  while( j < go[index].iNumObjects ){
             
    if( go[j].iType == 1 ){
    go[j].rc.top = rc.bottom;
    go[j].rc.bottom += rc.bottom-rc.top;
    go[j].rc.left = rc.left;
    go[j].rc.right = rc.right;
    }else{
    go[j].rc.top = rc.bottom;
    go[j].rc.bottom = rc.bottom-rc.top;
    go[j].rc.left = rc.left;
    go[j].rc.right = rc.right;
    size(&go[j], 0, 1, rc);
    }
    j++;
    }
  }

---

If you're compiling as c++ (which use of type 'bool' would seem to imply) then you should drop the 'typedef' from your struct definitions which would allow you to eliminate the void*, eg:

Code:

---

struct GRIDOBJECT_STRUCT{
  LPSTR            lpText,lpValue;
  int              id,iIndex,iNumObjects,iType,iValue;
  bool              bState,bValue;
  GRIDOBJECT_STRUCT *objects;
  RECT rc;
  };
 
GRIDOBJECT_STRUCT GRIDOBJECT;

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You would obviously have to amend your other structure (MITH32GRIDSTRUCT) accordingly but at least you would be able to access the objects as you more or less originally intended.

I don't know why I have ever been using typedef but I changed the struct and it works great (apart from the operand problem by using -> instead of . :)

Thanks a bunch!