Re: [boost] [config] Macro for null pointer

Subject: Re: [boost] [config] Macro for null pointer
From: Marshall Clow (mclow.lists_at_[hidden])
Date: 2012-12-07 21:59:36

On Dec 7, 2012, at 2:06 PM, "Jeffrey Lee Hellrung, Jr." <jeffrey.hellrung_at_[hidden]> wrote:

> On Fri, Dec 7, 2012 at 1:54 PM, Marshall Clow <mclow.lists_at_[hidden]> wrote:
> 
>> On Dec 7, 2012, at 12:14 PM, Daniel Russel <drussel_at_[hidden]> wrote:
>> 
>>> 
>>>> Well, I think some individuals here (I'd put myself in that camp) are
>>>> opposed to injecting anything into the global namespace if it can be
>>>> helped, and here it certainly can be helped. So if we add a nullptr
>>>> emulation in Boost, it's going to have to be paired with a using macro,
>> a
>>>> different name (i.e., boost::nullptr_), or both. If no one will use this
>>>> utility given the latter imperfections, I'm fine with just dropping the
>>>> proposal altogether and everyone can go back to using NULL or C++11.
>>> Just to put in my vote for not putting anything in the global namespace
>> but providing a "BOOST_USING_NULLPTR" macro. We keep our nullptr emulation
>> in our library namespace too and would gladly switch to a boost one.
>> 
>> We've already got:
>>        BOOST_NO_CXX11_NULLPTR
>> 
>> 
>> http://www.boost.org/doc/libs/1_52_0/libs/config/doc/html/boost_config/boost_macro_reference.html#boost_config.boost_macro_reference.macros_that_describe_c__11_features_not_supported
> 
> 
> Yes, the definition of BOOST_USING_NULLPTR depends on whether
> BOOST_NO_CXX11_NULLPTR is defined :) It's just a convenience macro
> equivalent to
> 
> #ifndef BOOST_NO_CX11_NULLPTR
> using ::boost::nullptr;
> #endif

That was what I wanted to be sure of; that we didn't introduce (yet) another config macro when we already had one.

-- Marshall

Marshall Clow     Idio Software   <mailto:mclow.lists_at_[hidden]>

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