Re: [boost] Fix for:: [bind] bug when used together with function.hppon BCB

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-02-18 10:09:33

Douglas Gregor wrote:
> On Wednesday 18 February 2004 06:23 am, Pavel Vozenilek wrote:
>> [Problem with <bind.hpp> and <function.h> on BCC 6.4]
>>
>> I found what;s the cause: <boost/mem_fn.hpp> is included
>> by <function.hpp> and so if one writes:
>>
>> ----------------
>> #include <boost/function.hpp>
>> #define BOOST_MEM_FN_ENABLE_FASTCALL
>> #include <boost/bind.hpp>
>> ----------------
>>
>> it results with Bind using differently pre-processed <mem_fn.hpp>
>> than it is expected.
>>
>>
>>
>> Bellow is solution to produce clean error message
>> when this situation happens:
>
> Thanks. Peter, can you commit this or something like it?

I appreciate Pavel's taking the time to identify the problem, but I'm
reluctant to commit his fix. The problem is not specific to
BOOST_MEM_FN_ENABLE_FASTCALL; any Boost macro that affects code (and nearly
all of them do) can cause a similar error when it's being inconsistently
defined in one file and not in another, or in the middle of the includes, as
in this case. Macros should be defined project-wide, with -D or in the
project settings.

I will, however, definitely mention this in the bind/mem_fn documentation.
Several times. In bold. :-)