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

13 Mar 2009

      Hi Steven,

And thanks for the reply.

Like I said, we assume that there is a subtle error in our 
implementation of the (derived) classes.

Generally speaking we would have the following structure:

Axis [pure virtual, abstract]
{
}

AxisBase : public Axis [abstract due to a few functions, Could that be 
an issue???]
{
}

AxisAlpha : public AxisBase [actual implementations]
{
}

On another note: All of this is legacy code so I can't really mess 
around to much with it or post complete parts - not that I think it 
would really help.

Again I was just looking for maybe another hint on 'how' to proceed and 
maybe leverage certain tricks in BOOST or VS2008 that I don't know yet :)

In any case thanks a lot again for even reading this gibberish!

A full error message would be:

----------------------------------------------------------------------
[...]\boost\concept_check.hpp(250) : error C2259: 'MotionControl::Axis': 
cannot instantiate abstract class due to following members:

'MotionControl::MoCon &MotionControl::Axis::MoCon(void)' : is abstract
[...]\main\applications\motion\axis.hpp(75) : see declaration of 
'MotionControl::Axis::MoCon'

'boost::shared_ptr<T> MotionControl::Axis::Motor(unsigned int)' : is 
abstract
with
[
     T=MotionControl::Motor
]
[...]\main\applications\motion\axis.hpp(81) : see declaration of 
'MotionControl::Axis::Motor'

'const MotionControl::MotorIdList 
&MotionControl::Axis::MotorIdList(void)' : is abstract
[...]\main\applications\motion\axis.hpp(86) : see declaration of 
'MotionControl::Axis::MotorIdList'

'const MotionControl::MotorList &MotionControl::Axis::MotorList(void)' : 
is abstract
[...]\main\applications\motion\axis.hpp(91) : see declaration of 
'MotionControl::Axis::MotorList'

'unsigned int MotionControl::Axis::Info(MotionControl::Info &)' : is 
abstract
[...]\main\applications\motion\axis.hpp(99) : see declaration of 
'MotionControl::Axis::Info'

'bool MotionControl::Axis::InfoMotor(MotionControl::Info &,unsigned 
int)' : is abstract
[...]\main\applications\motion\axis.hpp(106) : see declaration of 
'MotionControl::Axis::InfoMotor'

'MotionControl::Status 
MotionControl::Axis::SetPosition(MotionControl::Parameter::PositionTarget::value_type)' 
: is abstract
[...]\main\applications\motion\axis.hpp(123) : see declaration of 
'MotionControl::Axis::SetPosition'

[...]\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
]
[...]\include\propertycontainer.h(1159) : see reference to function 
template instantiation 'DataObjectPtr 
CreateDataObjectMotionControl::Axis(boost::shared_ptr<T>)' being compiled
with
[
     T=MotionControl::Axis
]
[...]\main\applications\stage\stagemotion.cxx(4922) : see reference to 
function template instantiation 'void 
PropertyContainer::UpdatePropertyStageControl::StageMotionProperty::AxisOptics(const 
StageControl::StageMotionProperty::AxisOptics::value_type &,bool)' being 
compiled
----------------------------------------------------------------------------

On 3/13/2009 1:50 PM, Steven Watanabe wrote:
...
AMDG
Tobias Alte wrote:
...
After switching from BOOST 1.33.0 to 1.34.1 (and also from VS2005 ->
VS2008) we got a couple of problems with "cannot instantiate abstract
class" errors.
The application compiles fine in the setup VS2005 + BOOST 1.33.0 but
suddenly started to throw a couple of "cannot instantiate abstract
class" errors when using VS2008 + BOOST 1.34.1 .
The errors itself get reported for 'concept_check.hpp' but that header
did not change between the two BOOST releases (as far as I know - I
think I made a diff with no results).
I believe that the issue is most likely related to the
boost::shared_ptr's to templated classes in our code.
I already solved a few of these errors that arose thanks to slightly
different types in the method definitions thanks to VS2008 having more
built in types.
However, the current "cannot instantiate abstract class" errors are
persistently eluding my grasp. And the compiler is not helpful with
just reporting the error in 'concept_check.hpp' and not where it
really is.
Can you post the full error message?
In Christ,
Steven Watanabe