Re: Template class to obtain members function result type

From:

Abhishek Padmanabh <abhishek.padmanabh@gmail.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 16 May 2007 09:45:53 CST

Message-ID:

<1179313094.256412.24840@n59g2000hsh.googlegroups.com>

On 16 May, 15:11, Piotr Jachowicz <pjach...@gmail.com> wrote:

I'm aware of specializations solution. But my Seq classes are
generated from CORBA IDL sequences and I have hundrets of them in my
project - it means hundrets of specializations that makes project hard
to understand and maintain. Morover if IDL change I'll have to keep
all synchronizations sync. What's I was looking for more elegant
solution.

Can you not have a typedef for the Res_type with your Seq classes? And
all types of Seq provide this typedef. So, let's assume if Seq is a
template on Res type, we would have:

    template<Res>
    struct Seq
    {
        typedef Res res_type;
        //other things
    };

and then,

    template<typename Seq, typename Res = Seq::res_type >
    SeqIter<Seq, Res> getBegin(Seq seq, Res res);

or you can even do without the second template type parameter since
you can always get through the public typedef where you need. For ex:

    template<typename Seq>
    SeqIter<Seq> getBegin(Seq seq, typename Seq::res_type res);

--
      [ See http://www.gotw.ca/resources/clcm.htm for info about ]
      [ comp.lang.c++.moderated. First time posters: Do this! ]