Re: [Boost-users] [serialization] conflicting declaration(BOOST_CLASS_EXPORT)

Subject: Re: [Boost-users] [serialization] conflicting declaration(BOOST_CLASS_EXPORT)
From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2008-09-19 08:09:02

jens weller wrote:
> Robert Ramey wrote:
>> try the following re export:
>>
>> a) re-read the manual regarding boost class export
> I did, any points you think about?
>> b) Try using BOOST_CLASS_EXPORT only once.
> 
> So far I thought after each class I could just set a 
> BOOST_CLASS_EXPORT($classname),
> as far as its derived from a serializable class.
> So, how to use it "only once"?
> Should I put those all in one file instead? ("exportmodel.hpp" f.e.)

Hi Jens,

I think Robert means that BOOST_CLASS_EXPORT($classname) may only be 
expanded once in your program for a particular class name. And per the 
docs this expansion must occur within the context of all archive types 
that will be used to serialize the class.

So rather than placing these macro calls in headers(which may be 
included in multiple translation units), place them in a cpp file that 
first includes the desired archive headers. Typically this would be in 
the class' implementation file. In the past I had placed them all in a 
single file, but quickly found the MSVC7.1 compiler limits, and had to 
break them up into export1.cpp, export2.cpp, ...

Jeff Flinn