2.95: Internal compiler error (template instantiation)

[Vince Del Vecchio <vince dot delvecchio at analog dot com>]

When I compile the attached program with gcc 2.95, I get:

bug.cc: In method `void value_list::append<_List_iterator<pointer_val<value>,const pointer_val<value> &,const pointer_val<value> *> >(_List_iterator<pointer_val<value>,const pointer_val<value> &,const pointer_val<value> *>, _List_iterator<pointer_val<value>,const pointer_val<value> &,const pointer_val<value> *>)':
bug.cc:51:   instantiated from here
bug.cc:55: Internal compiler error.

gcc version 2.95 19990728 (release)
sparc-sun-solaris2.5.1

-Vince Del Vecchio
vince.delvecchio@analog.com
#include <list>

template <class valtype>
class pointer_val {
  public:
    typedef valtype value_type;
    pointer_val () : val (0), count (0) { }
    pointer_val (const value_type& v)
	: val (new valtype(v)), count (new int (1)) { }
    pointer_val (const pointer_val& v)
	: val (v.val), count (v.count) { if (count) ++*count; }
    ~pointer_val () { delref (); }

    pointer_val& operator= (const pointer_val& v) {
      if (v.count) ++*v.count;
      delref ();
      val = v.val;
      count = v.count;
      return *this;
    }
    const value_type& operator* () const { return *val; }
    value_type& operator* () { return *operator-> (); }
    const value_type* operator-> () const { return val; }
    value_type* operator-> () {
      if (*count == 1) return val;
      val = new valtype(*val);
      --*count;
      count = new int (1);
      return val;
    }
  private:
    value_type *val;
    int *count;
    void delref () { if (count && !--*count) { delete val; delete count; } }
};

class value { };

typedef pointer_val<value> any_value;

class value_list : public value {
  protected:
    const value *x;
    std::list<any_value> elts;
    value_list& operator+= (const value_list& src) {
      append (src.elts.begin(), src.elts.end());
      return *this;
    }
    template <class in> void append (in s, in t) {
      any_value v = *x;
      for (in i = s; i != t; ++i)
	*v = **i;
    }
};

bug.ii.gz