[Boost-users] [mpl] Inheriting from each type in a sequence

From: Scott Meyers (usenet_at_[hidden])
Date: 2007-03-27 20:57:45

Given some base class,

   class Base { virtual ~Base(){} };

I want to be able to implement this:

   template<typename Seq>
   const Base& createObject()
   {
     // return an object that inherits from Base and every type in Seq
   }

The problem is how to create the type of object I want.

mpl::inherit is almost what I need, but it takes as template parameters each 
type to inherit from, and I don't have discrete types, I have a sequence of 
types.  mpl::inherit_linearly takes a sequence and would work for my purposes 
(which is to create an object that I can later check via dynamic_cast to see if 
it inherits from a given type), but it works only with forward sequences, and 
I'll typically have an mpl::set.  I could copy the contents of Seq into an 
mpl::vector and go from there, but that seems kind of gross.

Is there a good way to solve this problem that I am overlooking?

Thanks,

Scott