Using method function pointers in C++

[Pankaj]

Hello friends,

I am implementing something like

PM
|------------------------------------------------------
| | |
| | ------- -| send_if( data) |
| | M | |
| | | |
| | -------- | | |
| | | |
-----------------------------------------|-------------
|
PS |
|--------------------------------------------------------------
| | |
| | ------- | receive_if( data) |
| | S | |
| | | |
| | --------| |
| | |
------------------- --------------------------------------------

In this implementation, control flow starts with M's executeM() method.
executeM() is supposed to pass data to interface, say send_if( char *).
send_if( char *data); passes on this data to SInterface
send_if( char *data)
{
receive_if( data);
}

receive_if( ) collects this data and passes on to S by

receive_if( char * data)
{
executeS( data);
}
this will transfer data to S and S can display or do whatever it wants.
*************** *****

The class structure which i have created for this is :

1. File named: M_if.h
class M_if
{
public:
void send_if( char *);

};

*****
2. File: M.h
class M
{
char *data;
public:
M( )
{
data = new char[5];
data = "C++";
}

void executeM()
{
funcPtr_sendIf( data);
}

/// A fucntion pointer to store send_if() address.
void ( *funcPtr_sendIf ) ( char *);

};
class PM: public M_if
{
public:
M *m;

PM() // constructor
{
m = new M();
m-> funcPtr_sendIf = &send_if;
}

//// Send interface present with PM
void send_if()
{
funcPtr_receive If( data);
}

void ( *funcPtr_receiv eIf) ( char *);
};

******
3. File named: S_if.h

class S_if
{
public:
void receive_if( char *);

};

*****
2. File: S.h
class S
{
char *data;
public:
S() { } /// constructor

//// S Execution function, to display data
void executeS( char * data)
{
cout << " Data is : " << data;
}

};
class PS: public S_if
{
public:
S *s;

PS()
{
s = new S();
}

void receive_if( char * data)
{
s->executeS( data);
}
};

******

4. TopM

class TopM
{
PM *pm;
PS *ps;

public:
TopM ()
{

pm = new PM();
ps = new PS();

//// Interconnecting by assigning function pointer
pm->funcPtr_receiv eIf = &(ps->receive_if);
}
};

*************** *************** *************** ***

Of course, it doesn't get compiled.

I went through function pointer implementations and whatever i could
understand was what i have done in this example.

Please guide in this journey through method function pointer in C++

[lyang2]

You can not define the function pointer of one class as so.
/// A fucntion pointer to store send_if() address.
void ( *funcPtr_sendIf ) ( char *);

If I didn't remember wrong, it should be
void(M_inf::*fu ncPtr_sendif)(c har*).

Very strange? Yes, C++ has more strange syntax.

Regards.

Kandy
Pankaj wrote:

Hello friends,

I am implementing something like

PM
|------------------------------------------------------
| | |
| | ------- -| send_if( data) |
| | M | |
| | | |
| | -------- | | |
| | | |
-----------------------------------------|-------------
|
PS |
|--------------------------------------------------------------
| | |
| | ------- | receive_if( data) |
| | S | |
| | | |
| | --------| |
| | |
------------------- --------------------------------------------

In this implementation, control flow starts with M's executeM() method.
executeM() is supposed to pass data to interface, say send_if( char *).
send_if( char *data); passes on this data to SInterface
send_if( char *data)
{
receive_if( data);
}

receive_if( ) collects this data and passes on to S by

receive_if( char * data)
{
executeS( data);
}
this will transfer data to S and S can display or do whatever it wants.
*************** *****

The class structure which i have created for this is :

1. File named: M_if.h
class M_if
{
public:
void send_if( char *);

};

*****
2. File: M.h
class M
{
char *data;
public:
M( )
{
data = new char[5];
data = "C++";
}

void executeM()
{
funcPtr_sendIf( data);
}

/// A fucntion pointer to store send_if() address.
void ( *funcPtr_sendIf ) ( char *);

};
class PM: public M_if
{
public:
M *m;

PM() // constructor
{
m = new M();
m-> funcPtr_sendIf = &send_if;
}

//// Send interface present with PM
void send_if()
{
funcPtr_receive If( data);
}

void ( *funcPtr_receiv eIf) ( char *);
};

******
3. File named: S_if.h

class S_if
{
public:
void receive_if( char *);

};

*****
2. File: S.h
class S
{
char *data;
public:
S() { } /// constructor

//// S Execution function, to display data
void executeS( char * data)
{
cout << " Data is : " << data;
}

};
class PS: public S_if
{
public:
S *s;

PS()
{
s = new S();
}

void receive_if( char * data)
{
s->executeS( data);
}
};

******

4. TopM

class TopM
{
PM *pm;
PS *ps;

public:
TopM ()
{

pm = new PM();
ps = new PS();

//// Interconnecting by assigning function pointer
pm->funcPtr_receiv eIf = &(ps->receive_if);
}
};

*************** *************** *************** ***

Of course, it doesn't get compiled.

I went through function pointer implementations and whatever i could
understand was what i have done in this example.

Please guide in this journey through method function pointer in C++