Re: [boost] boost::noncopyable and DLL usage

From: John Maddock (john_at_[hidden])
Date: 2004-12-20 12:15:32

> Wouldn't it be better to change the class to use the __declspec(export)
> as others do?
> Or would this not solve the problem?
> At least I am unsure what would happen when trying to mix DLL and static
> boost libs that both derive from noncopyable.

I think it would be OK to delare an all-header class as 
__declspec(dllimport), but I'm not completely sure (where does the RTTI 
information end up if there is no source file?  I think this normally gets 
placed in the cpp file that has the first non-inline member function, but 
I'm not completely sure).

> BTW. this seems to me only a special case to a more general question.
> When using a DLL version of a class that derives from some other class,
> this would force every other lib that uses the same base, also to be
> used in DLL version. Is this correct?

Correct, the problem comes when you're using third party code, which uses 
other third party code and so on, just try using std::list<myclass> in an 
exported class and you'll see what I mean.  See also the discussion of 
dependencies at http://www.boost.org/more/separate_compilation.html#dlls

John.