Problems with temporaries and C++ spec

[Garrett Kajmowicz <gkajmowi@tbaytel.net>]

I'm working on my own C++ library for embedded applications (cxx.uclibc.org) 
and while implementing valarray I came across a problem with private copy 
contructors.  The following code works in GCC 3.3.5, but not in GCC 3.4.2

#include <iostream>

class copy_to;

class hidden_copying{
public:
        friend class copy_to;
        friend class copy_from;

private:
        hidden_copying() : q(0) {  }
        hidden_copying(const hidden_copying &);
        hidden_copying & operator=(const hidden_copying &);
        int q;
};

class copy_to{
public:
        friend class copy_from;
        copy_to() : p (0) { }
        copy_to(const hidden_copying & h) : p(h.q) {  }
        int getval() const{
                return p;
        }
private:
        int p;
};

class copy_from{
public:
        friend class hidden_copying;
        copy_from() : r(0) {  }
        copy_from(const int i) : r(i) {  }
        copy_from(const copy_from & f) : r(f.r) {  }
        hidden_copying data() const{
                hidden_copying retval;
                retval.q = r;
                return retval;
        }

private:
        int r;
};


int main(){
        copy_from a(5);
        copy_to b(a.data());
        std::cout << "Value of copy_to: " << b.getval() << std::endl;
        return 0;
}

With gcc 3.4.2 I receive the following error message:
../temporarytest.cpp: In function `int main()':
../temporarytest.cpp:12: error: `hidden_copying::hidden_copying(const 
hidden_copying&)' is private
../temporarytest.cpp:48: error: within this context

Without breaking valarray spec (in the above case, amounting to making any of 
the copy constructors of hidden_copying public), how can I get the above code 
work work properly.   If There is no way, than please explain how to 
reconsile behaviors with spec definition of std::slice_array.

Thank you for your help.

-     Garrett