With -O0 the following is accepted, with -O1 it is rejected with

Parser.3.ii: In member function ‘void RepPtrStore<_Tp, _Bt>::_assign(_Tp*)
[with _Tp = YStatement, _Bt = YCode]’:
Parser.3.ii:11:   instantiated from ‘RepPtrStore<_Tp, _Bt>::~RepPtrStore()
[with _Tp = YStatement, _Bt = YCode]’
Parser.3.ii:21:   instantiated from here
Parser.3.ii:16: error: no matching function for call to
‘Rep::unref(YStatement*&)’
Parser.3.ii:3: note: candidates are: void Rep::unref() const
Parser.3.ii:4: note:                 static void Rep::unref(const Rep*)


testcase:

class Rep {
public:
    void unref() const { }
    static void unref (const Rep * obj_r) { obj_r->unref(); }
};
template<typename _Tp, typename _Bt = _Tp>
class RepPtrStore {
    _Tp * _obj;
    void _assign( _Tp * new_r );
public:
    ~RepPtrStore() { _assign( 0 ); }
};
template<typename _Tp,typename _Bt>
void RepPtrStore<_Tp,_Bt>::_assign( _Tp * new_r )
{
  Rep::unref( _obj );
}
class RepPtrBase { };
template<typename _Bt> class PtrBase : public RepPtrBase { };
template<typename _Tp, typename _Bt = _Tp>
class Ptr : public PtrBase<_Bt> {
    RepPtrStore<_Tp,_Bt> _ptr;
};
class YCode;
class YStatement;
typedef Ptr<YStatement,YCode> YStatementPtr;
extern template class RepPtrStore<YStatement,YCode>;
class ExecutionEnvironment {
    YStatementPtr m_statement;
    ~ExecutionEnvironment() { };
};

GCC 4.3 accepts the code unconditionally, so does EDG.


-- 
           Summary: [4.4 Regression] Inconsistent reject / accept of code
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39242