[boost] Re: [review results] hash functions accepted

From: Eric Niebler (eric_at_[hidden])
Date: 2005-03-23 13:01:21

Jonathan Wakely wrote:
> On Wed, Mar 23, 2005 at 04:06:09PM +0000, Joaquin M Lopez Munoz wrote:
> 
> 
>>"I can't think of any way that this extension could
>>break a conforming program, considering that users
>>are not permitted to forward-declare standard
>>library components"
>>
>>Is this really so? Why cannot I forward declare a
>>stdlib component?
> 
> 
> Opening namespace std for anything except specialisations of standard
> library templates (with user-defined types as parameters) is illegal.
> 

OK, but that has never stopped us (Boost) from doing it before. 
config/suffix.hpp defines std::min and std::max for non-compliant std 
libs. lambda/detail/operator_return_type_traits.hpp forward-declares 
std::complex<>. I don't see anything particularly wrong with that, 
except that perhaps forward-declarations of std types should be moved 
into the config sub-project to better handle the variety in different 
std libs.

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com