Hi,

I have two classes A and B as follows.
A has member data X and member functions P, Q, R. All P,Q,R access X
and Q calls P.
B is a derived class of another Class(which I don't go into) with
member functions D, E.

P in A calls D in B.
D in B calls Q, R in A.

It's a big recursion. Everything works if I move D,E to class A. But
how do I achieve above as value of X need to be used through the whole
program execution? I wanted to know if what I am trying to accomplish
is something doable or I need to redesign my class structures.

Thanks

me.devilspride@gmail.com wrote:
> Hi,
>
> I have two classes A and B as follows.
> A has member data X and member functions P, Q, R. All P,Q,R access X
> and Q calls P.
> B is a derived class of another Class(which I don't go into) with
> member functions D, E.
>
> P in A calls D in B.
> D in B calls Q, R in A.
>
> It's a big recursion. Everything works if I move D,E to class A. But
> how do I achieve above as value of X need to be used through the whole
> program execution? I wanted to know if what I am trying to accomplish
> is something doable or I need to redesign my class structures.
>
> Thanks

How about showing some actual code? Even something like:

class A
{
int X;
public:
P() {}
Q() {}
// ...
};

etc..

What your'e trying to describe in words is not clear.


--
Jim Langston
tazmaster@rocketmail.com

On Apr 4, 7:28pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> me.devilspr...@gmail.com wrote:
> > Hi,
>
> > I have two classes A and B as follows.
> > A has member data X and member functions P, Q, R. All P,Q,R access X
> > and Q calls P.
> > B is a derived class of another Class(which I don't go into) with
> > member functions D, E.
>
> > P in A calls D in B.
> > D in B calls Q, R in A.
>
> > It's a big recursion. Everything works if I move D,E to class A. But
> > how do I achieve above as value of X need to be used through the whole
> > program execution? I wanted to know if what I am trying to accomplish
> > is something doable or I need to redesign my class structures.
>
> > Thanks
>
> How about showing some actual code? Even something like:
>
> class A
> {
> int X;
> public:
> P() {}
> Q() {}
> // ...
>
> };
>
> etc..
>
> What your'e trying to describe in words is not clear.
>
> --
> Jim Langston
> tazmas...@rocketmail.com

I am sorry for that

class A {
int X;
public:
P() { Q(); }
Q() { D(); R(); }
R() { uses X }
};

class B: public someclass {
//inherited data from someclass
public:
D() {
Q(); //end condition for recursion depends on X
R();
}
};

I can't create D() in A as D() access private data in B. But D() calls
both Q() and R() and value of X has to be same everywhere. i.e. R()
called from D access the same X value that was used by class A. I
guess I need to pass around this pointer of A's object or X. I guess
it shouldn't be difficult but I am just blocked.
Hope this s.

me.devilspride@gmail.com wrote:
> On Apr 4, 7:28 pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
>> me.devilspr...@gmail.com wrote:
>>> Hi,
>>
>>> I have two classes A and B as follows.
>>> A has member data X and member functions P, Q, R. All P,Q,R access X
>>> and Q calls P.
>>> B is a derived class of another Class(which I don't go into) with
>>> member functions D, E.
>>
>>> P in A calls D in B.
>>> D in B calls Q, R in A.
>>
>>> It's a big recursion. Everything works if I move D,E to class A. But
>>> how do I achieve above as value of X need to be used through the
>>> whole program execution? I wanted to know if what I am trying to
>>> accomplish is something doable or I need to redesign my class
>>> structures.
>>
>>> Thanks
>>
>> How about showing some actual code? Even something like:
>>
>> class A
>> {
>> int X;
>> public:
>> P() {}
>> Q() {}
>> // ...
>>
>> };
>>
>> etc..
>>
>> What your'e trying to describe in words is not clear.
>>
>> --
>> Jim Langston
>> tazmas...@rocketmail.com
>
> I am sorry for that
>
> class A {
> int X;
> public:
> P() { Q(); }
> Q() { D(); R(); }
> R() { uses X }
> };
>
> class B: public someclass {
> //inherited data from someclass
> public:
> D() {
> Q(); //end condition for recursion depends on X
> R();
> }
> };
>
> I can't create D() in A as D() access private data in B. But D() calls
> both Q() and R() and value of X has to be same everywhere. i.e. R()
> called from D access the same X value that was used by class A. I
> guess I need to pass around this pointer of A's object or X. I guess
> it shouldn't be difficult but I am just blocked.
> Hope this s.

There is no relationship between A and B in your code. A does not create an
instance of B, or B A, A does not derive from B, nor B A. How does Q know
which instance of B to call D for? How does D know which instance of A to
call Q for? You either have to pass a B to A and/or an A to B.
class A {
{
int X;
public:
P(B& b) { Q( b ); }
Q(B& b) { b.D( this ); )
R( ) { uses X )
};

class B: public someclass {
public:
D( A& a ) {
a.Q( this );
a.R();
}


--
Jim Langston
tazmaster@rocketmail.com

On Apr 4, 8:52pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> me.devilspr...@gmail.com wrote:
> > On Apr 4, 7:28 pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> >> me.devilspr...@gmail.com wrote:
> >>> Hi,
>
> >>> I have two classes A and B as follows.
> >>> A has member data X and member functions P, Q, R. All P,Q,R access X
> >>> and Q calls P.
> >>> B is a derived class of another Class(which I don't go into) with
> >>> member functions D, E.
>
> >>> P in A calls D in B.
> >>> D in B calls Q, R in A.
>
> >>> It's a big recursion. Everything works if I move D,E to class A. But
> >>> how do I achieve above as value of X need to be used through the
> >>> whole program execution? I wanted to know if what I am trying to
> >>> accomplish is something doable or I need to redesign my class
> >>> structures.
>
> >>> Thanks
>
> >> How about showing some actual code? Even something like:
>
> >> class A
> >> {
> >> int X;
> >> public:
> >> P() {}
> >> Q() {}
> >> // ...
>
> >> };
>
> >> etc..
>
> >> What your'e trying to describe in words is not clear.
>
> >> --
> >> Jim Langston
> >> tazmas...@rocketmail.com
>
> > I am sorry for that
>
> > class A {
> > int X;
> > public:
> > P() { Q(); }
> > Q() { D(); R(); }
> > R() { uses X }
> > };
>
> > class B: public someclass {
> > //inherited data from someclass
> > public:
> > D() {
> > Q(); //end condition for recursion depends on X
> > R();
> > }
> > };
>
> > I can't create D() in A as D() access private data in B. But D() calls
> > both Q() and R() and value of X has to be same everywhere. i.e. R()
> > called from D access the same X value that was used by class A. I
> > guess I need to pass around this pointer of A's object or X. I guess
> > it shouldn't be difficult but I am just blocked.
> > Hope this s.
>
> There is no relationship between A and B in your code. A does not create an
> instance of B, or B A, A does not derive from B, nor B A. How does Q know
> which instance of B to call D for? How does D know which instance of A to
> call Q for? You either have to pass a B to A and/or an A to B.
> class A {
> {
> int X;
> public:
> P(B& b) { Q( b ); }
> Q(B& b) { b.D( this ); )
> R( ) { uses X )
>
> };
>
> class B: public someclass {
> public:
> D( A& a ) {
> a.Q( this );
> a.R();
>
> }
>
> --
> Jim Langston
> tazmas...@rocketmail.com

Thanks for the reply, that actually was my problem. Actually in my
case there will be just one instance of A and B. But there isn't just
one class B, there are lots of classes derived from a parent class. I
am actually creating objects for these classes, kind of linked list. A
has functions for creating a list, but it may be nested that's why
there is a recursion. I guess passing A to B in my case is good. Thank
you.

On Apr 4, 9:34pm, me.devilspr...@gmail.com wrote:
> On Apr 4, 8:52pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
>
>
>
> > me.devilspr...@gmail.com wrote:
> > > On Apr 4, 7:28 pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> > >> me.devilspr...@gmail.com wrote:
> > >>> Hi,
>
> > >>> I have two classes A and B as follows.
> > >>> A has member data X and member functions P, Q, R. All P,Q,R access X
> > >>> and Q calls P.
> > >>> B is a derived class of another Class(which I don't go into) with
> > >>> member functions D, E.
>
> > >>> P in A calls D in B.
> > >>> D in B calls Q, R in A.
>
> > >>> It's a big recursion. Everything works if I move D,E to class A. But
> > >>> how do I achieve above as value of X need to be used through the
> > >>> whole program execution? I wanted to know if what I am trying to
> > >>> accomplish is something doable or I need to redesign my class
> > >>> structures.
>
> > >>> Thanks
>
> > >> How about showing some actual code? Even something like:
>
> > >> class A
> > >> {
> > >> int X;
> > >> public:
> > >> P() {}
> > >> Q() {}
> > >> // ...
>
> > >> };
>
> > >> etc..
>
> > >> What your'e trying to describe in words is not clear.
>
> > >> --
> > >> Jim Langston
> > >> tazmas...@rocketmail.com
>
> > > I am sorry for that
>
> > > class A {
> > > int X;
> > > public:
> > > P() { Q(); }
> > > Q() { D(); R(); }
> > > R() { uses X }
> > > };
>
> > > class B: public someclass {
> > > //inherited data from someclass
> > > public:
> > > D() {
> > > Q(); //end condition for recursion depends on X
> > > R();
> > > }
> > > };
>
> > > I can't create D() in A as D() access private data in B. But D() calls
> > > both Q() and R() and value of X has to be same everywhere. i.e. R()
> > > called from D access the same X value that was used by class A. I
> > > guess I need to pass around this pointer of A's object or X. I guess
> > > it shouldn't be difficult but I am just blocked.
> > > Hope this s.
>
> > There is no relationship between A and B in your code. A does not create an
> > instance of B, or B A, A does not derive from B, nor B A. How does Q know
> > which instance of B to call D for? How does D know which instance of A to
> > call Q for? You either have to pass a B to A and/or an A to B.
> > class A {
> > {
> > int X;
> > public:
> > P(B& b) { Q( b ); }
> > Q(B& b) { b.D( this ); )
> > R( ) { uses X )
>
> > };
>
> > class B: public someclass {
> > public:
> > D( A& a ) {
> > a.Q( this );
> > a.R();
>
> > }
>
> > --
> > Jim Langston
> > tazmas...@rocketmail.com
>
> Thanks for the reply, that actually was my problem. Actually in my
> case there will be just one instance of A and B. But there isn't just
> one class B, there are lots of classes derived from a parent class. I
> am actually creating objects for these classes, kind of linked list. A
> has functions for creating a list, but it may be nested that's why
> there is a recursion. I guess passing A to B in my case is good. Thank
> you.

I still have some problems, Here A creates an instance of B and calls
member function of B.

///A.h
class A {
{
int X;
public:
P() { Q(); }
Q() {
R();
bb = new B();
bb.D( this ); )
R() { uses X )

};

///B.h
class B: public someclass {
public:
D( A& a ) {
a.Q();
a.R();
};

But there is a cyclic dependency and forward declaration of A in B
doesn't work. What should I do?
Any would be very appreciated. Thanks.

On 5 Apr, 21:08, me.devilspr...@gmail.com wrote:
> On Apr 4, 9:34pm, me.devilspr...@gmail.com wrote:
>
>
>
>
>
> > On Apr 4, 8:52pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
>
> > > me.devilspr...@gmail.com wrote:
> > > > On Apr 4, 7:28 pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> > > >> me.devilspr...@gmail.com wrote:
> > > >>> Hi,
>
> > > >>> I have two classes A and B as follows.
> > > >>> A has member data X and member functions P, Q, R. All P,Q,R accessX
> > > >>> and Q calls P.
> > > >>> B is a derived class of another Class(which I don't go into) with
> > > >>> member functions D, E.
>
> > > >>> P in A calls D in B.
> > > >>> D in B calls Q, R in A.
>
> > > >>> It's a big recursion. Everything works if I move D,E to class A. But
> > > >>> how do I achieve above as value of X need to be used through the
> > > >>> whole program execution? I wanted to know if what I am trying to
> > > >>> accomplish is something doable or I need to redesign my class
> > > >>> structures.
>
> > > >>> Thanks
>
> > > >> How about showing some actual code? Even something like:
>
> > > >> class A
> > > >> {
> > > >> int X;
> > > >> public:
> > > >> P() {}
> > > >> Q() {}
> > > >> // ...
>
> > > >> };
>
> > > >> etc..
>
> > > >> What your'e trying to describe in words is not clear.
>
> > > >> --
> > > >> Jim Langston
> > > >> tazmas...@rocketmail.com
>
> > > > I am sorry for that
>
> > > > class A {
> > > > int X;
> > > > public:
> > > > P() { Q(); }
> > > > Q() { D(); R(); }
> > > > R() { uses X }
> > > > };
>
> > > > class B: public someclass {
> > > > //inherited data from someclass
> > > > public:
> > > > D() {
> > > > Q(); //end condition for recursion depends on X
> > > > R();
> > > > }
> > > > };
>
> > > > I can't create D() in A as D() access private data in B. But D() calls
> > > > both Q() and R() and value of X has to be same everywhere. i.e. R()
> > > > called from D access the same X value that was used by class A. I
> > > > guess I need to pass around this pointer of A's object or X. I guess
> > > > it shouldn't be difficult but I am just blocked.
> > > > Hope this s.
>
> > > There is no relationship between A and B in your code. A does not create an
> > > instance of B, or B A, A does not derive from B, nor B A. How does Q know
> > > which instance of B to call D for? How does D know which instance of A to
> > > call Q for? You either have to pass a B to A and/or an A to B.
> > > class A {
> > > {
> > > int X;
> > > public:
> > > P(B& b) { Q( b ); }
> > > Q(B& b) { b.D( this ); )
> > > R( ) { uses X )
>
> > > };
>
> > > class B: public someclass {
> > > public:
> > > D( A& a ) {
> > > a.Q( this );
> > > a.R();
>
> > > }
>
> > > --
> > > Jim Langston
> > > tazmas...@rocketmail.com
>
> > Thanks for the reply, that actually was my problem. Actually in my
> > case there will be just one instance of A and B. But there isn't just
> > one class B, there are lots of classes derived from a parent class. I
> > am actually creating objects for these classes, kind of linked list. A
> > has functions for creating a list, but it may be nested that's why
> > there is a recursion. I guess passing A to B in my case is good. Thank
> > you.
>
> I still have some problems, Here A creates an instance of B and calls
> member function of B.
>
> ///A.h
> class A {
> {
> int X;
> public:
> P() { Q(); }
> Q() {
> R();
> bb = new B();
> bb.D( this ); )
> R() { uses X )
>
> };
>
> ///B.h
> class B: public someclass {
> public:
> D( A& a ) {
> a.Q();
> a.R();
>
> };
>
> But there is a cyclic dependency and forward declaration of A in B
> doesn't work. What should I do?
> Any would be very appreciated. Thanks.- Hide quoted text -
>
> - Show quoted text -

You're thinking in Java/C# terms - separate the interface from
the implementation and all will be well:

// A.h
class A {
int X;
public:
void Q();
void R();
};

///B.h
class B: public someclass {
public:
D( A& a );
};

//A.cpp
#include "A.h"
#include "B.h"
void A::Q() {
R();
bb = new B();
bb.D( this );
}
void A::R() { uses X }

//B.cpp
#include "B.h"
#include "A.h"
void B:( A& a ) {
a.Q();
a.R();
}

On Apr 5, 5:20pm, tragomaskhalos <dave.du.verg...@logicacmg.com>
wrote:
> On 5 Apr, 21:08, me.devilspr...@gmail.com wrote:
>
>
>
> > On Apr 4, 9:34pm, me.devilspr...@gmail.com wrote:
>
> > > On Apr 4, 8:52pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
>
> > > > me.devilspr...@gmail.com wrote:
> > > > > On Apr 4, 7:28 pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> > > > >> me.devilspr...@gmail.com wrote:
> > > > >>> Hi,
>
> > > > >>> I have two classes A and B as follows.
> > > > >>> A has member data X and member functions P, Q, R. All P,Q,R access X
> > > > >>> and Q calls P.
> > > > >>> B is a derived class of another Class(which I don't go into) with
> > > > >>> member functions D, E.
>
> > > > >>> P in A calls D in B.
> > > > >>> D in B calls Q, R in A.
>
> > > > >>> It's a big recursion. Everything works if I move D,E to class A.But
> > > > >>> how do I achieve above as value of X need to be used through the
> > > > >>> whole program execution? I wanted to know if what I am trying to
> > > > >>> accomplish is something doable or I need to redesign my class
> > > > >>> structures.
>
> > > > >>> Thanks
>
> > > > >> How about showing some actual code? Even something like:
>
> > > > >> class A
> > > > >> {
> > > > >> int X;
> > > > >> public:
> > > > >> P() {}
> > > > >> Q() {}
> > > > >> // ...
>
> > > > >> };
>
> > > > >> etc..
>
> > > > >> What your'e trying to describe in words is not clear.
>
> > > > >> --
> > > > >> Jim Langston
> > > > >> tazmas...@rocketmail.com
>
> > > > > I am sorry for that
>
> > > > > class A {
> > > > > int X;
> > > > > public:
> > > > > P() { Q(); }
> > > > > Q() { D(); R(); }
> > > > > R() { uses X }
> > > > > };
>
> > > > > class B: public someclass {
> > > > > //inherited data from someclass
> > > > > public:
> > > > > D() {
> > > > > Q(); //end condition for recursion depends on X
> > > > > R();
> > > > > }
> > > > > };
>
> > > > > I can't create D() in A as D() access private data in B. But D() calls
> > > > > both Q() and R() and value of X has to be same everywhere. i.e. R()
> > > > > called from D access the same X value that was used by class A. I
> > > > > guess I need to pass around this pointer of A's object or X. I guess
> > > > > it shouldn't be difficult but I am just blocked.
> > > > > Hope this s.
>
> > > > There is no relationship between A and B in your code. A does notcreate an
> > > > instance of B, or B A, A does not derive from B, nor B A. How does Q know
> > > > which instance of B to call D for? How does D know which instanceof A to
> > > > call Q for? You either have to pass a B to A and/or an A to B.
> > > > class A {
> > > > {
> > > > int X;
> > > > public:
> > > > P(B& b) { Q( b ); }
> > > > Q(B& b) { b.D( this ); )
> > > > R( ) { uses X )
>
> > > > };
>
> > > > class B: public someclass {
> > > > public:
> > > > D( A& a ) {
> > > > a.Q( this );
> > > > a.R();
>
> > > > }
>
> > > > --
> > > > Jim Langston
> > > > tazmas...@rocketmail.com
>
> > > Thanks for the reply, that actually was my problem. Actually in my
> > > case there will be just one instance of A and B. But there isn't just
> > > one class B, there are lots of classes derived from a parent class. I
> > > am actually creating objects for these classes, kind of linked list. A
> > > has functions for creating a list, but it may be nested that's why
> > > there is a recursion. I guess passing A to B in my case is good. Thank
> > > you.
>
> > I still have some problems, Here A creates an instance of B and calls
> > member function of B.
>
> > ///A.h
> > class A {
> > {
> > int X;
> > public:
> > P() { Q(); }
> > Q() {
> > R();
> > bb = new B();
> > bb.D( this ); )
> > R() { uses X )
>
> > };
>
> > ///B.h
> > class B: public someclass {
> > public:
> > D( A& a ) {
> > a.Q();
> > a.R();
>
> > };
>
> > But there is a cyclic dependency and forward declaration of A in B
> > doesn't work. What should I do?
> > Any would be very appreciated. Thanks.- Hide quoted text -
>
> > - Show quoted text -
>
> You're thinking in Java/C# terms - separate the interface from
> the implementation and all will be well:
>
> // A.h
> class A {
> int X;
> public:
> void Q();
> void R();
>
> };
>
> ///B.h
> class B: public someclass {
> public:
> D( A& a );
>
> };
>
> //A.cpp
> #include "A.h"
> #include "B.h"
> void A::Q() {
> R();
> bb = new B();
> bb.D( this );}
>
> void A::R() { uses X }
>
> //B.cpp
> #include "B.h"
> #include "A.h"
> void B:( A& a ) {
> a.Q();
> a.R();
>
> }
>
>

OK, but adding header files that way wouldn't cause any problems. I
did the same but got errors like - "C++ forbids declaration with no
type". But I will again try, Thanks.

On 6 Apr, 00:07, me.devilspr...@gmail.com wrote:
> On Apr 5, 5:20pm, tragomaskhalos <dave.du.verg...@logicacmg.com>
> wrote:
>
>
>
>
>
> > On 5 Apr, 21:08, me.devilspr...@gmail.com wrote:
>
> > > On Apr 4, 9:34pm, me.devilspr...@gmail.com wrote:
>
> > > > On Apr 4, 8:52pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
>
> > > > > me.devilspr...@gmail.com wrote:
> > > > > > On Apr 4, 7:28 pm, "Jim Langston" <tazmas...@rocketmail.com> wrote:
> > > > > >> me.devilspr...@gmail.com wrote:
> > > > > >>> Hi,
>
> > > > > >>> I have two classes A and B as follows.
> > > > > >>> A has member data X and member functions P, Q, R. All P,Q,R access X
> > > > > >>> and Q calls P.
> > > > > >>> B is a derived class of another Class(which I don't go into) with
> > > > > >>> member functions D, E.
>
> > > > > >>> P in A calls D in B.
> > > > > >>> D in B calls Q, R in A.
>
> > > > > >>> It's a big recursion. Everything works if I move D,E to class A. But
> > > > > >>> how do I achieve above as value of X need to be used through the
> > > > > >>> whole program execution? I wanted to know if what I am trying to
> > > > > >>> accomplish is something doable or I need to redesign my class
> > > > > >>> structures.
>
> > > > > >>> Thanks
>
> > > > > >> How about showing some actual code? Even something like:
>
> > > > > >> class A
> > > > > >> {
> > > > > >> int X;
> > > > > >> public:
> > > > > >> P() {}
> > > > > >> Q() {}
> > > > > >> // ...
>
> > > > > >> };
>
> > > > > >> etc..
>
> > > > > >> What your'e trying to describe in words is not clear.
>
> > > > > >> --
> > > > > >> Jim Langston
> > > > > >> tazmas...@rocketmail.com
>
> > > > > > I am sorry for that
>
> > > > > > class A {
> > > > > > int X;
> > > > > > public:
> > > > > > P() { Q(); }
> > > > > > Q() { D(); R(); }
> > > > > > R() { uses X }
> > > > > > };
>
> > > > > > class B: public someclass {
> > > > > > //inherited data from someclass
> > > > > > public:
> > > > > > D() {
> > > > > > Q(); //end condition for recursion depends on X
> > > > > > R();
> > > > > > }
> > > > > > };
>
> > > > > > I can't create D() in A as D() access private data in B. But D()calls
> > > > > > both Q() and R() and value of X has to be same everywhere. i.e. R()
> > > > > > called from D access the same X value that was used by class A. I
> > > > > > guess I need to pass around this pointer of A's object or X. I guess
> > > > > > it shouldn't be difficult but I am just blocked.
> > > > > > Hope this s.
>
> > > > > There is no relationship between A and B in your code. A does not create an
> > > > > instance of B, or B A, A does not derive from B, nor B A. How does Q know
> > > > > which instance of B to call D for? How does D know which instance of A to
> > > > > call Q for? You either have to pass a B to A and/or an A to B.
> > > > > class A {
> > > > > {
> > > > > int X;
> > > > > public:
> > > > > P(B& b) { Q( b ); }
> > > > > Q(B& b) { b.D( this ); )
> > > > > R( ) { uses X )
>
> > > > > };
>
> > > > > class B: public someclass {
> > > > > public:
> > > > > D( A& a ) {
> > > > > a.Q( this );
> > > > > a.R();
>
> > > > > }
>
> > > > > --
> > > > > Jim Langston
> > > > > tazmas...@rocketmail.com
>
> > > > Thanks for the reply, that actually was my problem. Actually in my
> > > > case there will be just one instance of A and B. But there isn't just
> > > > one class B, there are lots of classes derived from a parent class. I
> > > > am actually creating objects for these classes, kind of linked list.A
> > > > has functions for creating a list, but it may be nested that's why
> > > > there is a recursion. I guess passing A to B in my case is good. Thank
> > > > you.
>
> > > I still have some problems, Here A creates an instance of B and calls
> > > member function of B.
>
> > > ///A.h
> > > class A {
> > > {
> > > int X;
> > > public:
> > > P() { Q(); }
> > > Q() {
> > > R();
> > > bb = new B();
> > > bb.D( this ); )
> > > R() { uses X )
>
> > > };
>
> > > ///B.h
> > > class B: public someclass {
> > > public:
> > > D( A& a ) {
> > > a.Q();
> > > a.R();
>
> > > };
>
> > > But there is a cyclic dependency and forward declaration of A in B
> > > doesn't work. What should I do?
> > > Any would be very appreciated. Thanks.- Hide quoted text -
>
> > > - Show quoted text -
>
> > You're thinking in Java/C# terms - separate the interface from
> > the implementation and all will be well:
>
> > // A.h
> > class A {
> > int X;
> > public:
> > void Q();
> > void R();
>
> > };
>
> > ///B.h
> > class B: public someclass {
> > public:
> > D( A& a );
>
> > };
>
> > //A.cpp
> > #include "A.h"
> > #include "B.h"
> > void A::Q() {
> > R();
> > bb = new B();
> > bb.D( this );}
>
> > void A::R() { uses X }
>
> > //B.cpp
> > #include "B.h"
> > #include "A.h"
> > void B:( A& a ) {
> > a.Q();
> > a.R();
>
> > }
>
> OK, but adding header files that way wouldn't cause any problems. I
> did the same but got errors like - "C++ forbids declaration with no
> type". But I will again try, Thanks.- Hide quoted text -
>
> - Show quoted text -

Sorry, I forgot the required forward declarations
in the B header:

///B.h
class A; // <===== forgot this.
class B: public someclass {
public:
D( A& a );
};