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

Subject: Re: [boost] Pervasive dependency upon mpl::bool_
From: Peter Dimov (lists_at_[hidden])
Date: 2014-06-03 07:55:59

Andrey Semashev wrote:

> So what do you think, is it worth to split MPL?

I do think that it will be worth it, although I'm not entirely sure that 
this needs to be an immediate priority of ours. If we have the core type 
traits, much of the focus on MPL might go away, although dependencies have 
their own insidious ways of getting back into the tent.

value_init is an example of what happens. You have a library of 147 (say) 
headers. One of them (for_each.hpp) is affected by a compiler bug. Someone 
fixes it by including value_init.hpp into it. Now everyone who includes some 
of the other 146 headers acquires a module-level dependency on whatever 
hosts value_init.

A simple core part is less prone to this dependency creep.

I agree that the core type traits will help more, though. Many modules will 
be able to avoid any contact with MPL if we have those.