Re: [boost] [wave] preprocessor directives in output

Subject: Re: [boost] [wave] preprocessor directives in output
From: Eric Niebler (eniebler_at_[hidden])
Date: 2014-01-21 19:31:58

On 01/21/2014 04:20 PM, pmenso57_at_[hidden] wrote:
> Eric, just be very careful about what macros expand when.  E.g. the expression:
> 
> !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
> 
> will get expanded on the first preprocessor pass to something like
> 
> !defined(1)
> 
> (or whatever it expands to)

Thanks for the warning, and that makes sense, but it's not what I'm
seeing. I'm seeing wave spit out:

# if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)

instead of:

# if !defined(1)

Why would that be? Regardless, I can turn off expansion of this macro
during preprocessing with wave's -N switch, so there's a fix should I
ever need it.

Eric