Re: [boost] Pervasive dependency upon mpl::bool_

Subject: Re: [boost] Pervasive dependency upon mpl::bool_
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2014-06-01 18:26:26

On Monday 02 June 2014 00:30:12 Peter Dimov wrote:
> 
> > Would it be possible to define true_ and false_ with a lot less code?
> 
> Possibly. The problem is that mpl::bool_ is owned by MPL. It can impose all
> sorts of (potentially changing, although this is not an issue at the moment)
> requirements on them. None of those are actually needed by people doing tag
> dispatching, but we can't just kidnap mpl::true_ and mpl::false_ and decree
> that they shall henceforth live in Core.

What are those requirements? Are they actually changing that often? I bet if 
we drop support for ancient compilers, then mpl::bool_, mpl::if_ and friends 
will become quite trivial and can be placed in Core just fine.