Re: [Boost-users] Preprocessor Question

From: Peter Bartlett (pete_at_[hidden])
Date: 2008-05-06 10:08:37

Quoting Ed Keith <e_d_k_at_[hidden]>:

>
> --- Peter Bartlett <pete_at_[hidden]> wrote:
>
>> Quoting Ed Keith <e_d_k_at_[hidden]>:
>>
>> > [...]
>> >
>> > BOOST_PP_IF(abc == abc, foo, bar)
>> >
>> > I get an error.
>> >
>> > Is it possible to do something like this? If so,
>> what
>> > am I doing wrong?
>>
>> I think you have to use BOOST_PP_IF(
>> BOOST_PP_EQUAL(abc,abc) , foo,
>> bar ) here.
>
> I tried that, but apparently BOOST_PP_EQUAL only takes
> int values.
>
> Thank for the suggestion though,
>
>   -EdK

Ok. BOOST_PP_IF has a similar restriction, so you probably can't do  
what you want with it. Be sure though that even the '#if' version is  
doing what you want - for example the following program prints 1 on my  
compiler (VC9):

#if foo == bar
   int baz() { return 1; }
#else
   int baz() { return 0; }
#endif

#include <iostream>
int main()
{
   std::cout << "\n" << baz() << "\n";
}