"Johan Nilsson" <r.johan.nilsson@gmail.com> writes:
I plan to use Boost.Parameter for its capability of providing named parameter to these object types. However, I have one problem in this approach: Since Boost.Parameter requires that the function processing the ArgumentPack to be a template, I cannot make it virtual (a member function template cannot be virtual) in my pure abstract base interface. Furthermore, due to the lack of "virtual" member function, I cannot use the base class pointer to provide these named parameters to some subclasses.
Depends on what you actually want to do. Perhaps you could use something like the template pattern (pseudo-code):
----- struct Parameters : boost::parameter::parameters< ... > {};
struct Base { BOOST_PARAMETER_MEMFUN(void, Work, 1, 4, Parameters) { DoWork( p[arg1], p[arg2|0], p[arg3|1] ... ); }
private: virtual void DoWork(actual, args, goes, here) = 0; };
class Derived : public Base { virtual void DoWork(actual, args, goes, here) { ... use args ... } };
class Derived2 : public Base { virtual void DoWork(actual, args, goes, here) { ... use args ... } };
-----
I've used something similar myself, hope that gives an idea on how to solve your problem.
Excellent answer. Also, be sure to check out the latest version of Boost.Parameter that is in CVS (and on the release branch). It's considerably easier to use. -- Dave Abrahams Boost Consulting www.boost-consulting.com