Re: [boost] A proposal for the creation of a new module, Core Type Traits

Subject: Re: [boost] A proposal for the creation of a new module, Core Type Traits
From: Peter Dimov (lists_at_[hidden])
Date: 2015-01-08 14:44:42

John Maddock wrote:
> But my broader point was that this generates two separate traits called 
> is_pod (for example), with slightly different interfaces and conceptual 
> requirements on usage.  IMO this is a "really bad thing" and we can do 
> much better.

Well yes, it does, and this is kind of the point, isn't it?

I already explained why I want the core type traits to have a minimal 
interface: so that one can specialize or implement a core type trait without 
having to include any type traits header, core or otherwise. You define 
::value and that's it, you have a bona fide trait.

Others obviously don't like this interface, they want something "better". 
But anything better makes it worse for my purposes, so the improved version 
is of no use to me. So we'll be going to be stuck with two interfaces, and 
the best we can do is implement the richer interface in terms of the spartan 
one, so that specializations of the lower layer are automatically reflected 
in the higher one.