Re: [Boost-users] [Fusion] Building parameter list for fusion::invoke

Subject: Re: [Boost-users] [Fusion] Building parameter list for fusion::invoke
From: Nat Linden (nat_at_[hidden])
Date: 2011-01-23 21:56:55

On Sun, Jan 23, 2011 at 2:40 AM, TONGARI <tongari95_at_[hidden]> wrote:

Use Fusion's MPL  sequences adapters, so you can have:
>
> typedef typename
>         mpl::transform
>         <
>             parameter_types
>           , from_data_source<mpl::_1>
>
>           , mpl::back_inserter<mpl::vector<> >
>         >::type
> data_source_provider; // a MPL  sequence
>
> And invoke as:
>
> fs::invoke(f, data_source_provider());
>
> where from_data_source<T> is defined as:
>
> template<class T>
> struct from_data_source
> {
>     operator T() const
>
>     {
>         return data_source<T>().pop();
>     }
> };
>
> Maybe your data_source<T>() is some singleton for the data source?
>

Hmm! That seems more succinct than the explicit recursion in the
interpreter.hpp example.

Apologies if this is a silly question, but suppose the object from which I'd
like to obtain parameter values is locally constructed rather than global?
How would I parameterize the mpl::transform expression above to pass in that
object?