Yet another template bug in gcc-2.95.1

[Wolfgang Glas <Wolfgang dot Glas at hfm dot tu-graz dot ac dot at>]

Hi there,

  I have just been further distilling a bug report from Peter Vanroose, which he
sent to the newsgroup gnu.g++.bug.

  The main problem is that the member function operators interact with the
friend operators although they take different arguments.

//------------file: friend.cc-------------------------------------------------

typedef long int ptrdiff_t;

// Three forward declarations, which are necessary to conform with
// the new ANSI C++ standard. The template functions must be declared
// before they are used in a friend specification.

template <class RandomAccessIterator> class _r__It;

template <class RandomAccessIterator> 
ptrdiff_t operator- (const _r__It <RandomAccessIterator>& x,
		     const _r__It <RandomAccessIterator>& y);

template <class RandomAccessIterator>
_r__It<RandomAccessIterator> operator+ (ptrdiff_t n,
					const _r__It <RandomAccessIterator>& x);

template <class RandomAccessIterator> 
class _r__It {
    typedef ptrdiff_t distance_type;
    typedef _r__It <RandomAccessIterator> self;

  // now I bring in the friends...
    friend   distance_type operator- <>  (const self& x, const self& y);
    friend   self operator+ <>  (distance_type n, const self& x);

protected:
    RandomAccessIterator current;
public:
    _r__It () {}
    _r__It (const RandomAccessIterator& x) : current(x) {}

  // These are two different +,- operators, which badly interact with the
  // friends from above in gcc-2.95.1 ......

#ifdef MORE_OPERATORS
    self operator+(distance_type n) const {
        return self(current - n);
    }

    self operator-(distance_type n) const {
        return self(current + n);
    }
#endif
};

template class _r__It < bool  const *>;
template class _r__It < bool  *>;

//------------end of file: friend.cc------------------------------------------


---------compile session------------
/home/wglas/CC/this_and_that > gcc -v
Reading specs from /usr/local/lib/gcc-lib/mips-sgi-irix6.5/2.95.1/specs
gcc version 2.95.1 19990816 (release)
/home/wglas/CC/this_and_that > gcc -c friend.cc
/home/wglas/CC/this_and_that > gcc -DMORE_OPERATORS -c friend.cc
friend.cc: In instantiation of `_r__It<const bool *>':
friend.cc:46:   instantiated from here
friend.cc:24: invalid use of undefined type `class _r__It<const bool *>'
friend.cc:44: forward declaration of `class _r__It<const bool *>'
friend.cc:23: invalid use of undefined type `class _r__It<const bool *>'
friend.cc:44: forward declaration of `class _r__It<const bool *>'
friend.cc: In instantiation of `_r__It<bool *>':
friend.cc:47:   instantiated from here
friend.cc:24: invalid use of undefined type `class _r__It<bool *>'
friend.cc:44: forward declaration of `class _r__It<bool *>'
friend.cc:23: invalid use of undefined type `class _r__It<bool *>'
friend.cc:44: forward declaration of `class _r__It<bool *>'
/home/wglas/CC/this_and_that > gcc -Vegcs-2.91.66 -v
Reading specs from /usr/local/lib/gcc-lib/mips-sgi-irix6.5/egcs-2.91.66/specs
gcc driver version 2.95.1 19990816 (release) executing gcc version egcs-2.91.66
/home/wglas/CC/this_and_that > gcc -Vegcs-2.91.66 -DMORE_OPERATORS -c friend.cc
------end of compile session--------

  Maybe this helps to find out more about template problems with gcc-2.95.1

    Wolfgang

--
Mag. Wolfgang Glas
Institut fuer hydraulische Stroemungsmaschinen
Kopernikusgasse 24                              Phone:++43/316/873/7578
A-8010 Graz                                     Fax:  ++43/316/873/7577

mailto:Wolfgang.Glas@hfm.tu-graz.ac.at   
http://fhysmsg01.tu-graz.ac.at/Wolfgang.Glas/