Re: [boost] [type_traits][core] modularisation and moving stuff about (again)

Subject: Re: [boost] [type_traits][core] modularisation and moving stuff about (again)
From: Glen Fernandes (glen.fernandes_at_[hidden])
Date: 2018-08-22 18:18:10

On Wed, Aug 22, 2018 at 1:55 PM John Maddock wrote:
> So... I have a couple of PR's to move some of type_traits into config so it can be used by core.

To be clear, these are intrinsics that we are discussing moving. I
believe these in general are better suited for Config, even for other
libraries that may not depend on Core but will still depend on Config.

i.e. We're talking about things like BOOST_IS_FINAL(T) which may or
may not be defined on a given implementation (e.g. to __is_final(T) or
some  other implementation specific intrinsic).

A library author might have use for the intrinsic, but not the trait.
For example, boost::is_final<T>::value might be false because the
implementation has no intrinsic, but that doesn't mean you can derive
from T if it really is final. On the other hand, if
defined(BOOST_IS_FINAL) then BOOST_IS_FINAL(T) enables that.

The intrinsic macros aside, whether the traits like boost::is_empty<T>
should be in Core is a slightly different question.

Glen