[boost] Re: loki::type_list == boost::mpl::list_node

From: Andrei Alexandrescu (andrewalex_at_[hidden])
Date: 2002-04-14 13:43:50

"Hamish Mackenzie" <hamish_at_[hidden]> wrote in message
news:1018803083.2507.1250.camel_at_lightening.firestream.co.uk...
> I think a lot of confusion has resulted from people, including
myself,
> thinking that mpl::type_list and loki::type_list are (or should be)
the
> same thing.  Both have advantages and disadvantages.
> If mpl and loki are to be integrated it is loki::type_list and
> mpl::list_node that need to be merged.

Thanks Hamish for a refreshingly constructive and useful motion.

> loki::type_list could be renamed to type_list_node.
>
> Then mpl list_node could be split into type_list_node and
value_list_node
> (reducing the number of template args from 4 to 2).
>
> This would leave us with
>   mpl::type_list == loki::TYPE_LIST_NN
>   mpl::type_list_node == loki::type_list_node

I believe this is a nice approach that could make everybody happy.
Then, Loki's dependency of mpl would be precisely one little header.

> This will have some implications. Here are the ones I can see
>
> * To use a mpl::type_list with a loki class you will have to use
::type
> eg. mpl::type_list< int, float >::type
> This problem should go away once template typedefs are available.
>
> * To use other mpl containers with loki you will need to convert
them (I
> assume this is a common requirement with a simple solution).

I believe this is reasonable. Any other caveats?

Andrei