Re: [boost] [type_erasure] Review started (July 18-27, 2012)

Subject: Re: [boost] [type_erasure] Review started (July 18-27, 2012)
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2012-07-23 10:35:29

On Wednesday 18 July 2012 01:13:20 Lorenzo Caminiti wrote:
> Hello all,
> 
> *** The review of Steven Watanabe's proposed Boost.TypeErasure library
> begins on July 18, 2012 and ends on July 27, 2012. ***

Hi,

This is not yet a complete review but rather some thoughts and questions I 
came up with as I read the documentation and the source code. I did not follow 
the discussion so my apologies if these have already been answered.

1. As I can see, the implementation contains a function table to implement 
concepts, am I right? Why this table is stored per-object and not created 
statically, for every stored type/concept combination? Considering the number 
of concepts, this table can take much space in every "any" instance.

2. Is it possible to convert between "any" instances with different concept 
sets or value types? For instance, are these possible?

 any< my_concepts, _self& > ref_a;
 any< my_concepts, _self > a = ref_a;

or

 any< mpl::vector<
   addable<>,
   incrementable<>,
   decrementable<> >
 > a;

 any< mpl::vector<
   addable<> >
 > b = a;