[boost] Re: Formal Review: FOREACH macro

From: David Abrahams (dave_at_[hidden])
Date: 2005-05-02 15:55:55

"Eric Niebler" <eric_at_[hidden]> writes:

> Gennadiy Rozental wrote:
>> "Eric Niebler" <eric_at_[hidden]> wrote in message
>> news:427652AD.1020900_at_boost-consulting.com...
>> 
>>> Besides, eliminating the rvalue requirement won't simplify the code
>>> because much of that machinery is needed anyway to prevent the
>>> macro args from being reevaluated. The rvalue stuff practically
>>> falls out of that.
>> Lets see: to support rvalues you need:
>> # include <new>
>> # include <boost/aligned_storage.hpp>
>> # include <boost/utility/enable_if.hpp>
>> # include <boost/type_traits/is_array.hpp>
>> struct rvalue_probe
>> template<typename T>
>> struct simple_variant
>> cheap_copy
>> Quite a lot actually.
>> 
>
>
> True, but much of this is only needed for the *const* rvalue stuff. If 
> there were general agreement that there's fat to trim (is there?), 
> dropping *const* rvalue support would be an easy target. 

Don't do it! I plan to write some functions that return const
rvalues.  Plus, Scott Meyers recommends it, so you'll encounter it.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com