Re: [boost] New dependency report

Subject: Re: [boost] New dependency report
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2014-06-07 11:13:15

El 06/06/2014 23:40, Peter Dimov escribió:
> John Maddock wrote:
>> I'm tied of saying this.... but if mpl::bool_ and int_ were moved out
>> of MPL full, either to core, or to some mpl_core, then there's no need
>> to split type_traits anymore.
>
> The question is: what is the minimal conforming implementation of a type
> trait? Is it
>
> template<class T> struct something
> {
>     bool const value = false;
> }
>
> or is it, instead,
>
> template<class T> struct something: mpl::false_
> {
> };

I would say the first one. I use my own true_/false_ wrappers in my 
libraries just to avoid MPL dependencies.

To be standard conforming, we would need to add 
"std::integral_constant<bool, false>" as "type" member. But IMHO this 
seems a bit redundant.

Best,

Ion