error C2259: 'user_param::UserParamB2<std::string>' : cannot instantiate abstract cl

[vikash121]

Hello

I am not able to figure out the reason for the following error:
error C2259: 'user_param::UserParamB2<std::string>' : cannot instantiate abstract class
3> due to following members:

'bool user_param::UserParamBase::readonly(bool)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(128) : see declaration of 'user_param::UserParamBase::readonly'
3> 'bool user_param::UserParamBase::readonly(void)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(127) : see declaration of 'user_param::UserParamBase::readonly'
3> 'SIZE user_param::UserParamBase::winSize(void)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(129) : see declaration of 'user_param::UserParamBase::winSize'
3> 'bool user_param::UserParamBase::get(void)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(132) : see declaration of 'user_param::UserParamBase::get'
3> 'void user_param::UserParamBase::update(void)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(133) : see declaration of 'user_param::UserParamBase::update'
3> 'void user_param::UserParamBase::create(CWnd *,const RECT &)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(134) : see declaration of 'user_param::UserParamBase::create'
3> 'void user_param::UserParamBase::close(void)' : is abstract
3> c:\qc\qc_daq\src\hfgui3\userparambase.h(135) : see declaration of 'user_param::UserParamBase::close'

any help or suggestion is deeply appreciated
tons of Thanks in advance

[weaknessforcats]

YOu are attempting to create an object that contains, or inherits, a pure virtual function.

By definition, you cannot call a pure virtual function using an object of the class that defines it. To make sure you don't try this, the compiler prevents you from creating that object.