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From: dgorton@jupiter.newcastle.edu.au (David Mark Gorton)
Newsgroups: comp.lang.c++
Subject: pointers to member functions
Message-ID: <dgorton.676272036@jupiter.newcastle.edu.au>
Date: 7 Jun 91 05:20:36 GMT
Sender: news@neddy.newcastle.edu.au
Distribution: comp
Organization: Uni of Newcastle, Australia
Lines: 72

In Stroustrups "The C++ Programming Language" pp 153-154 an example is given 
of how to "fake" the expression of the type of a pointer to a member function. 
Has this been standardised ? (I dont have access to a copy of the ARM at the 
moment, though I have one on order.)

I am writing a class definition for TCP connections using the Transport Level
Interface and have the following class definition

class tcp {     // TCP connection
    private :
	// Data members
	...
    public :
	...
        void ConnectionRelease(void);
	...
};

The sample program in the Sun Network Programming Guide has a C function

connrelease()
{
    ...
}

and in the server function

run_server(...)
{
    signal(SIGPOLL, connrelease);
    if (ioctl(conn_fd, I_SETSIG, S_INPUT) < 0) 
	...
}
	
I wish to do the equivalent in C++ using ConnectionRelease() from class tcp.

The header file for <sys/signal.h> on our SUN 3/80 has 

typedef void SIG_FUNC_TYP(int);
typedef SIG_FUNC_TYP *SIG_TYP;

extern "C" {
        SIG_TYP signal(int, SIG_TYP);
	...
};

The AT&T C++ Compiler accepts the following

    //
    // Fake type of pointer to member - See <signal.h> and "The C++ 
    // Programming Language" - Bjarne Stroustrup, pp 153-154 for details
    //
    SIG_TYP pf = SIG_TYP(&tcp::ConnectionRelease);

    signal(SIGPOLL, pf);
    if (ioctl(fdConnection, (int) I_SETSIG, (caddr_t) S_INPUT) < 0)


Is this correct (and the standard) ??

Thanks in advance,
Dave

---------------------------------------------------------------------------
Dave Gorton.     Department of Computer Science,
                 University of Newcastle,
                 Newcastle, 2308, Australia.       .-_|\
Telephone   :    (049) 216 034                    /     \
                                                  \.--._/
Internet    :    dgorton@cs.newcastle.edu.au           v
	 	 csdmg@cc.newcastle.edu.au
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