c++/4361: gcc 3.0.1 bogus ambiguity taking the address of a member template

[sebor at roguewave dot com]

>Number:         4361
>Category:       c++
>Synopsis:       gcc 3.0.1 bogus ambiguity taking the address of a member template
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Sep 19 09:26:01 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     sebor@roguewave.com
>Release:        gcc 3.0.1
>Organization:
>Environment:

>Description:
This is reduced from our auto_ptr testsuite. The compiler
is confused by the two conversion operators. 2.95.2 ICEs
on this code.

Regards
Martin
>How-To-Repeat:
$ cat t.cc ; g++ t.cc
template <class T>
class auto_ptr;

template <class T>
struct auto_ptr_ref
{
    template <class U>
    auto_ptr_ref (auto_ptr<U>&) throw () { }
};


template<class T>
struct auto_ptr
{
    template <class U>
    operator auto_ptr_ref<U>() throw () {
        return auto_ptr_ref<U>(*this);
    }

    template <class U>
    operator auto_ptr<U>() throw () {
        return auto_ptr<U>();
    }
};

struct B { };
struct D: B { };

int main ()
{
    auto_ptr<B> (auto_ptr<D>::*pf)() = &auto_ptr<D>::operator auto_ptr<B>;
}
t.cc: In function `int main()':
t.cc:32: no matches converting function `operator auto_ptr_ref<U>' to type 
   `struct auto_ptr<B> (struct auto_ptr<D>::*)()'
t.cc:16: candidates are: template<class U> auto_ptr::operator auto_ptr_ref<U>() 
   [with U = U, T = D]
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: