# Boost :

From: Pavel Kuznetsov (pavel_at_[hidden])
Date: 2003-09-30 07:54:53

It seems that boost code is written to avoid compilers warnings. Though
some warnings do slip into MSVC++ builds when boost headers are included.
Most (all?) of these are the warnings which are turned of by default. In
particular sometimes I can see C4668 warnings shown:

boost\boost\mem_fn.hpp(296) : warning C4668:
'__MWERKS__' is not defined as a preprocessor macro,
replacing with '0' for '#if/#elif'

Where boost\boost\mem_fn.hpp(296) is:

#if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) &&
!BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))

Where BOOST_WORKAROUND is:

# define BOOST_WORKAROUND(symbol, test) \
((symbol != 0) && (1 % (( (symbol test) ) + 1)))

It seems that in some places authors are aware of the problem stated.
E.g.: boost\boost\intrusive_ptr.hpp(124):

#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)

(Of course it is possible that in fact __SUNPRO_CC can be defined to 0 and
it is that case what is tested here...)

So I see two ways to eliminate the warning in question: either suppress it
with corresponding #pragmas, or rewrite BOOST_WORKAROUND so that it would
test whether 'symbol' is defined before comparing it to 0.

I could submit the patches for either of these. Which one do you prefer?
Or maybe I miss something and some other third way should be taken?

```--
Pavel
```