Re: [boost] typedefs within Concept or as Trait?

From: Doug Gregor (dgregor_at_[hidden])
Date: 2008-01-10 16:57:17

On Jan 10, 2008, at 4:54 PM, Gennadiy Rozental wrote:

> Doug Gregor <dgregor <at> osl.iu.edu> writes:
>> Traits classes are far better than nested typedefs, because one can
>> always specialize a traits class for an existing type---even if you
>> can't modify the type because it is built-in or comes from another
>> library that you can't modify.
>
> This is not exactly true if typedefs are part of some concepts types  
> used as a
> policies, right? This is true is we are talking about typedefs as  
> members of
> your primary template parameter type.

With policies... sure, nested types are okay there, because you  
typically have to code each policy class for a specific template  
anyway (and there generally isn't reuse of policies across libraries).

        - Doug