Hallo,
14.5.2 (1) states that member function templates of class templates
may be defined outside of their class template definition. However it
only provides an example where the member function template has a
function parameter whose type matches the template parameter. No
explicit mention is made of whether such an out of line definition is
allowed when a member function's template arguments cannot be deduced
from function arguments.

In my opinion the following syntax should be allowed:

template <typename T> struct A {
    template <typename U> void f();
};

template <typename T> template <typename U>
void A<T>::f<U>() {
}

int main() {
    A<int> a;
    a.f<double>();
}

This syntax is accepted by one out of the four compilers I tested.

Am I missing something? Should I rephrase this message as a defect
report?

Cheers,
Nicola Musatti

---
[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://www.comeaucomputing.com/csc/faq.html                      ]

On May 25, 4:25 am, gre...@pacbell.net (Greg Herlihy) wrote:
> On 5/24/07 12:39 PM, in article
> 1180001745.029006.204...@m36g2000hse.googlegroups.com, "Nicola Musatti"
>
> <nicola.musa...@gmail.com> wrote:
[...]
> According to the paragraph cited then, it is legal for any member function
> template - including one with non-deducible template type parameters - to be
> defined outside of its class definition.

You are right and as it often happens I realized it soon after
posting. I was misled by less than clear compiler error messages...

> > In my opinion the following syntax should be allowed:
>
> > template <typename T> struct A {
> >     template <typename U> void f();
> > };
>
> > template <typename T> template <typename U>
> > void A<T>::f<U>() {
> > }

.which pointed to the A<T>:: part of the above definition.

> No, f<U> would signify some kind of specialization of the f<> member
> template - and not its general definition. The correct definition of f()
> would be:
>
>      template <typename T> template <typename U>
>      void A<T>::f() {
>      }

Which is actually accepted by all the compilers I have available.

> > This syntax is accepted by one out of the four compilers I tested.
>
> It should not have been accepted by any C++ compiler.

Indeed.

Cheers,
Nicola Musatti

---
[ comp.std.c++ is moderated.  To submit articles, try just posting with ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu    ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://www.comeaucomputing.com/csc/faq.html                      ]