Re: [Boost-users] Problem with 'cannot instantiate abstract class' after switching from BOOST 1.33.0 to 1.34.1 (also VS2005 -> VS2008)

Subject: Re: [Boost-users] Problem with 'cannot instantiate abstract class' after switching from BOOST 1.33.0 to 1.34.1 (also VS2005 -> VS2008)
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2009-03-13 19:16:56

AMDG

I've tried to strip the error message down to the important parts.

Tobias Alte wrote:
> Generally speaking we would have the following structure:
>
> Axis [pure virtual, abstract]
> {
> }
>
> ----------------------------------------------------------------------
> [...]\boost\concept_check.hpp(250) : error C2259: 
> 'MotionControl::Axis': cannot instantiate abstract class due to 
> following members:
>
> [...]\include\dataobject.h(747) : see reference to class template 
> instantiation 'boost::CopyConstructibleConcept<TT>' being compiled
> with
> [
>     TT=MotionControl::Axis
> ]
> [...]\include\dataobject.h(1444) : see reference to class template 
> instantiation 'Data<_type>' being compiled
> with
> [
>     _type=MotionControl::Axis
> ] 

Why does Data require _type to be CopyConstructible?
If this concept requirement is correct, why is Data being
instantiated with MotionControl::Axis?

In Christ,
Steven Watanabe