circular definitions

[DNA7433]

its late and i don't feel like thinking about how i need to go about doing this so anyone who has run into this problem before could you please help?

i have two classes that refer back to each other and it can't compile in the normal fashion

thanx

[amac]

What is the error?

Are you using pointers to the other class, because you might be able to use forward declarations...

[CornedBee]

class b;
class a {
b* pb; };
class b {
a* pa; };

[DNA7433]

yes, thank you, that works

the only problem is im using a member function from one of the classes and its telling me the function doesn't exist?

would i need to do something like this?

class b
{
void nothing();
};

class a
{
void func()
{b->nothing();}

b* pb;
};

class b
{
void nothing()
{ cout << "nothing";}

a* pa;
};

[amac]

Originally posted by CornedBee
class b; <- This is a forward declaration.
class a {
b* pb; };
class b {
a* pa; };

That was just for DNA's info...

Umm the only thing I can suggest is... Do not "inline" the function that way. Move its definition into a source file. If you still want it inline you can specify that by placing the keyword "inline" before the function header.

[DNA7433]

ok, well the function is in a seperate file, i just did that for my little example

[DNA7433]

ok i think i got it now

i need to include all the .cpp code after ALL of the headers have been defined

[DNA7433]

i was wrong, it still doesn't work

i wish there were more people on this forum

[CornedBee]

always include all headers first.
inline functions are static by definition, so

// a .h file, included by both .cpp files
class a{
public:
  void foo();
};
// one .cpp file:
inline void a::foo()
{
  // code
}
// another .cpp file:
void main()
{
  a obj;
  obj.foo();  // linker error!
}

The functions only exist in the module they were defined in. Solution: put the functions in a special file (usual extension is .inl), then include this file at the end of the header.

// a.h
class a{
public:
 void foo();
};
#include "a.inl"

// a.inl
inline void foo()
{
  // foo
}

// some.cpp
void main()
{
  a obj;
  obj.foo();  // OK
}

// someother.cpp
void func()
{
  a obj;
  obj.foo();  // OK
}

You could also place the code in a.inl directly in a.h, but the separation makes it more readable.

[paradoxresolved]

How about:

class a
{
b thisb; // not a pointer!
}

class b
{
a* pa;
}

???

[CornedBee]

Possible, but you must reorder:

class a;
class b {
 a *pa;
};
class a {
 b ob;
};

[paradoxresolved]

Not sure why, but that doesn't seem to compile. . .

//{{AFX_INCLUDES()
#include "MyStatic.h"
//}}AFX_INCLUDES

class CInterfaceView : public CFormView
{
...
//{{AFX_DATA(CInterfaceView)
...
CMyStatic m_Att1Val;
...
//}}AFX_DATA
...
}


#include "interfaceView.h"
class CInterfaceView;
class CMyStatic: public CStatic
{
...
CInterfaceView* parentform;
...
}


That leads to over a thousand errors.

[CornedBee]

Remove the #include "interfaceView.h" from MyStatic.h.

There's also no reason to store the pointer you're storing. Just use GetParent (or GetParentWindow) and cast the result.

[paradoxresolved]

Sweet! Thanks again.