Const Friend?

[pocmatos]

Hi all,

Is it possible to declare a const friend or something. I wish to make
class B friend of class A but I don't want it to be changing A. It's a
read-only friend. Is this possible?

Thanks,

Paulo Matos

[Zara]

On 28 Nov 2005 01:41:02 -0800, po******@gmail.com wrote:

Hi all,

Is it possible to declare a const friend or something. I wish to make
class B friend of class A but I don't want it to be changing A. It's a
read-only friend. Is this possible?

Thanks,

Paulo Matos

class A {
/*...*/
friend class B;
/*...*/
};

class B {
/*...*/
void function(const class A& what)
{
/* this is the function that accesses A, only through what reference
and not using const_cast */}
};

[Neil Cerutti]

On 2005-11-28, po******@gmail.com <po******@gmail.com> wrote:

Is it possible to declare a const friend or something. I wish
to make class B friend of class A but I don't want it to be
changing A. It's a read-only friend. Is this possible?

Include an in-between friend that provides the access for the
members you want to share.

class A {
int x, y;
friend class B;
};

class B {
const int &x() const { return A::x; }
const int &y() const { return A::y; }
/* If they're really built-in types, you wouldn't necessarily use
references. But in general, you would. */
friend class C;
};

class C {
// Must use B::x() and B::y() to access A::x and A::y.
};

--
Neil Cerutti