[ns] pointers and addresses

[Jan Cerlot <cerlot@fokus.gmd.de>]

Hi,
I have created a new header. In this header, I have a field integer num_. I can 
change its value in my main program with the two lines :

hdr_rack* cr= (hdr_rack*)p->access(off_rack_);
cr->num()=value;

because, in my header, I have defined the function num() like this :

int& num() {return num_;}

But now, I would like to do the same with a pointer ptr_s_ to a structure.

I tried this : 

dyn_rack *ptr_s_;
dyn_rack* ptr_s() {return ptr_s_;} 

but when I try to change the value of this pointer in my main program, I have an 
error :
non-lvalue in assignment

So could anybody show me  the line to type to define the correct function in my 
header so I could change the value of the pointer ( ex.: so I could have the 
equivalency of ptr_s=malloc ... but with the function defined in my header as 
with num(), I want num=5, I write cr->num()=5 ).

Thank you.
   Jan.