Re: why creating pointer to reference member is illegal?

From:

"Bo Persson" <bop@gmb.dk>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 11 Mar 2009 02:50:46 CST

Message-ID:

<71ni3sFlvssrU1@mid.individual.net>

blargg wrote:

Now that the wrong question is out of the way, perhaps we can now
address your question of why one can't take a pointer to MEMBER
(not object) where the member is a reference. Just as a refresher,
this takes a pointer to member for a NON-reference type:

    typedef int T; // why doesn't this work if changed to int&?

    struct X { T i; };

    void example( X& x )
    {
        T X::*mptr = &X::i; // get pointer to member
        x.*mptr = 123; // now dereference it on an object
    }

Why can't we do the same thing when i is of type int&?

Because you cannot take the address of a reference. Ordinarily you
would get the address of the object referred to, but a class'
reference member in isolation doesn't refer to anything.

You are trying to get the location in the phonebook for an unlisted
number.

Bo Persson

--
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
[ comp.lang.c++.moderated. First time posters: Do this! ]