I'm neither an expertin C++ nor MFC programming, but the following lines of
code seems straight foward, but returns with an

error 2100: illegal indirection.

// create new CReference object
CReference *p_reference = (CReference*) new CReference;
// copy from addreference that belongs to a dialog
*p_reference = (CReference)adddia.addreference;
// sets internal integer value of p_reference., but causes a compilation
error
*p_reference->m_iID = 1;

If it makes a different, p_reference is later inserted into a COBArray

I actually managed to get round it doing adddia.addreference.m_iID = 1
before copying. But it's all a bit strange to me.

regards
H

See inline

"Henry" <abshhkc> skrev i en meddelelse
news:am52
> I'm neither an expertin C++ nor MFC programming, but the following lines
of
> code seems straight foward, but returns with an
>
> error 2100: illegal indirection.
>
> // create new CReference object
> CReference *p_reference = (CReference*) new CReference;
*****
It's not necessary to cast to the same type
*****

> // copy from addreference that belongs to a dialog
> *p_reference = (CReference)adddia.addreference;
> // sets internal integer value of p_reference., but causes a
compilation
> error
> *p_reference->m_iID = 1;
*****
Either call it like
*p_reference.m_iID = 1;
or
p_reference->m_iID = 1;
*****
[..]

Which line is the error on????

Anyway, you don't need to cast your new statement the return type and the
variable are the same

CReference *p_reference = new CReference;

Now as far as the assignment goes, does your CReference class have an =
operator?

*p_reference = (CReference)adddia.addreference;

Ali R.


"Henry" <abshhkc> wrote in message news:am52
[..]

And I missed the way you were accessing the variable inside p_reference.

either use a *p_reference.variable or p_reference->variable

Ali R.

"Ali R." <nospam> wrote in message
news:8956
[..]

Henry wrote:

> I'm neither an expertin C++ nor MFC programming, but the following lines of
> code seems straight foward, but returns with an
>
> error 2100: illegal indirection.
>
> // create new CReference object
> CReference *p_reference = (CReference*) new CReference;
> // copy from addreference that belongs to a dialog
> *p_reference = (CReference)adddia.addreference;
> // sets internal integer value of p_reference., but causes a compilation
> error
> *p_reference->m_iID = 1;

-> bounds tighter than *, so you have to use parens:

(*p_reference)->m_iID = 1;

hth
Paavo

Henry wrote:

> I'm neither an expertin C++ nor MFC programming, but the following lines of
> code seems straight foward, but returns with an
>
> error 2100: illegal indirection.
>
> // create new CReference object
> CReference *p_reference = (CReference*) new CReference;
> // copy from addreference that belongs to a dialog
> *p_reference = (CReference)adddia.addreference;
> // sets internal integer value of p_reference., but causes a compilation
> error
> *p_reference->m_iID = 1;

Sorry, pressed the send button too soon. Actually you have double
indirection here, but I suspect you only need one. You can write either

p_reference->m_iID = 1;

or

(*p_reference).m_iID = 1;

Paavo

Henry wrote:
> I'm neither an expertin C++ nor MFC programming, but the following lines of
> code seems straight foward, but returns with an
>
> error 2100: illegal indirection.
>
> // create new CReference object
> CReference *p_reference = (CReference*) new CReference;

You can:
CReference *p_reference= new CReference;

if you look at it like this:
CReference* p_reference= new CReference;

you will see that p_reference is a pointer to the object.


> // copy from addreference that belongs to a dialog
> *p_reference = (CReference)adddia.addreference;

if addreference is a CReference object, you only need to:
*p_reference= adddia.addreference;

You only need to cast if CReference is a base class of addreference. It
is always safer not to cast unless you absolutely know what you intend.

> // sets internal integer value of p_reference., but causes a compilation
> error
> *p_reference->m_iID = 1;

p_reference->m_iID = 1;
or:
(*p_reference).m_iID = 1;

But:
*p_reference.m_iID = 1;

will not work. the (.) takes precedence over (*) and tries to treat
p_reference as a reference. It is not a reference to the object, you
will get an error. That is why the prins in the 'or' example above.

> If it makes a different, p_reference is later inserted into a COBArray

Not at all.

> I actually managed to get round it doing adddia.addreference.m_iID = 1
> before copying. But it's all a bit strange to me.

You need to get a handle on the difference between a pointer to
something and the something and how they are represented in C++. Your
p_reference is a pointer (*p_reference) is a reference. A reference to
an object looks just like an object.
[..]