Re: [boost] Boost.Preprocessor: Alternatives to defined(x)

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-05 17:43:57

"Vesa Karvonen" <vesa_karvonen_at_[hidden]> writes:

> David Abrahams:
>>Paul Mensonides:
>> > The semantic change is that 'x' must not be a function-like macro.  What do
>> > you think?
>>
>>I think that rules out most of the use-cases Vesa was interested in
>>addressing with this :(
>
> Well, it does rule out some use-cases, and it is not ideal to have such limitations, but it should
> still be useful for testing whether an object-like macro, such as an include guard, or a config
> macro, has been defined. I think that there are many uses for the
> macro.

How can you use a macro which only tells you if a function-like macro
is defined to tell you if an object-like macro is defined?

If we could do that, couldn't you implement your original intended
semantics?

-- 
                       David Abrahams
   dave_at_[hidden] * http://www.boost-consulting.com
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