Re: [Boost-users] Boost preprocessor question

Subject: Re: [Boost-users] Boost preprocessor question
From: Tim Day (timday_at_[hidden])
Date: 2009-01-04 18:31:43

On Sun, 2009-01-04 at 22:53 +0100, Michiel Helvensteijn wrote:
> I would like something like this (how I think it might look):
> 
> CLASS(Foo, FROM(Bar))
>     CONSTRUCT()
>     CONSTRUCT(PAR(int, a, A), PAR(bool, b, B))
>     int A;
>     bool B;
> END_CLASS
> 
> to automatically become something like this:
> 
> class Foo : public Bar, public shared_from_this<Foo> {
>     private: Foo() {}
>     public: static shared_ptr<Foo> construct() {
>         return shared_ptr<Foo>(new Foo());
>     }
>     private: Foo(int a, bool b) : A(a), B(b) {}
>     public: static shared_ptr<Foo> construct(int a, bool b) {
>         return shared_ptr<Foo>(new Foo(a, b));
>     }
>     int A;
>     bool B;
> };

Have you considered how boost::tuple might help ?
A boost::tuple<int,bool> would seem to provide most of the above.
A simple template could provide a tuple-wrapping class restricting
allocation to the shared_ptr--returning construct method.  OK so you
wouldn't get to name the members, and the construct method itself would
presumably need to take a tuple (unless you provide sufficient templated
member functions to handle as many arguments as necessary).  I don't
know how important those aspects are to you though.

In my experience, trying to be too clever with the preprocessor results
in a nastier mess than the problem you were originally trying to solve.

Tim