Re: [boost] nested BOOST_FOREACH and -Wshadow

Subject: Re: [boost] nested BOOST_FOREACH and -Wshadow
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2009-02-07 17:01:09

David Abrahams wrote:
> on Sat Feb 07 2009, Sebastian Redl <sebastian.redl-AT-getdesigned.at> wrote:
> 
> F> John Bytheway wrote:
>>> I'd suggest a simpler (from the user perspective) solution would be to
>>> have BOOST_FOREACH paste __LINE__ into its variable names.  Then the
>>> problem would only occur if nested BOOST_FOREACHs were used on the same
>>> line.  Asking users not to do that seems a lot more reasonable than
>>> asking them not to use -Wshadow or not to use nested BOOST_FOREACHs at all.
>>>   
>> I'm pretty sure you'd need a special variant for MS compilers, since
>> their __LINE__ expansion is not cleanly pasteable. (You can use their
>> counting macro instead.)
> 
> Doesn't using BOOST_PP_CAT work?

Hmm, just tried and it works on VC9. It surely didn't on VC7.1.