specialization of friend template fct.

[Stefan Schwarzer <sts at ica1 dot uni-stuttgart dot de>]

We use the following idiom to hack around a problem in one of 
our compilers which does not correclty implement template friends. 
As I read the CD2, this code should be ok and it compiles with 
cxx-6.1 and KCC 3.3.
The latest ecgs-snapshot produces an internal error at the specialization
in line 39

23:50 margay_sts:~/bugs/kai> /local/egcs-19980608/bin/g++ simple_pair.cc
simple_pair.cc:39: Internal compiler error.
simple_pair.cc:39: Please submit a full bug report to `egcs-bugs@cygnus.com'.
23:54 margay_sts:~/bugs/kai> uname -a
OSF1 margay.ica1.uni-stuttgart.de V4.0 564.32 alpha
23:55 margay_sts:~/bugs/kai> cat simple_pair.cc


#include <iostream>

// offending statement:
// comment out to make bug (?) dissappear
using namespace std; 

class A{};
class OUT{};

OUT & operator<<(OUT &o, const A &a){ 
  std::cout << "OUT << A\n";
  return o; 
}

template<class T>
struct V {
  V(T *a_): a(a_){}

  // this is really a hack but should be ok according to CD2 14.5.3
  template<class S>
  friend OUT & operator<<(OUT &, const V<S> &);
 
  //friend OUT & operator<<(OUT &, const V<A> &);
  //friend OUT & operator<< <T>(OUT &, const V<T> &);
  //friend OUT &operator<< <A>(OUT &o, const V<A> &va);
private:
  T *a;
};

template<class T>
OUT &operator<< (OUT &o, const V<T> &v){
  std::cout << "OUT << V<T>\n";
  return o << *v.a;
}

// ok according to CD2 14.7            -- line 39
template<>
OUT &operator<< (OUT &o, const V<A> &va){
  // same behavior:  OUT &operator<< <A>(OUT &o, const V<A> &va){
  std::cout << "OUT << V<A>\n";
  return o << *va.a;
}

int main()
{  
  A a;
  OUT  o;
  o << V<A>(&a);
}