Re: [Boost-users] [interprocess] warning C4251: need dll-interface

On Wed, Apr 8, 2009 at 11:28 PM, Brent Arias wrote:

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I've defined a class to use within shared memory, and I've decorated it with a Windows _declspec(export) to expose it from a DLL.  When I compiled with VC 2008, I got this warning:

Warning C4251: class 'boost::interprocess::vector' needs to have dll-interface to be used by clients of 'MyClass'

There is an explanation of this problem at http://www.unknownroad.com/rtfm/VisualStudio/warningC4251.html. The short version is that it is nearly always ok to ignore the warning but there is real underlying risk of strange errors if you link libraries compiled with different compilers or compiler options.