Re: int (*&)()

From:

Victor Bazarov <v.Abazarov@comAcast.net>

Newsgroups:

comp.lang.c++

Date:

Mon, 08 Feb 2010 08:12:43 -0500

Message-ID:

<hkp2jq$4et$1@news.datemas.de>

Asif Zaidi wrote:

On Feb 8, 12:28 am, Syron <mr.sy...@googlemail.com> wrote:

Am 08.02.2010 04:45, schrieb Asif Zaidi:

What does the syntax in subject line mean - how should I read it.
Thanks
Asif

if this is a typedef (like 'int(*&func)()') it is a reference to a
pointer to a function that returns an int.

Kind regards, Syron

I am trying to implement the following and getting compile failure.
Any suggestions ?

typedef int (*& func_ptr1)();

int goo()
{
    cout << "un goo" << endl;
    return 0;
}

int main()
{

    func_ptr1 p1 = goo;
}

The error is below

1>d:\profiles\waz003\my documents\visual studio 2008\projects
\hw5_3\hw5_3\hw5_3.cpp(174) : error C2440: 'initializing' : cannot
convert from 'int (__cdecl *)(void)' to 'func_ptr1'

I believe the reference to non-const requires a modifiable l-value for
initialisation. Your 'goo' is not an lvalue. You can either do

    typedef int (* const & func_ptr_ref)();

    ...

        func_ptr_ref pr = goo;

or define a variable of the type 'pointer to function' and initialise
your reference with it:

    ...
    int main()
    {
         int (*some_fptr)();
         func_ptr1 p1 = some_fptr;
    }

V
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