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

On 3/27/07, Scott Meyers wrote:

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.

Thanks,

Scott

I'm probably won't use the correct mpl-isms, but something like template <typename Seq> struct inherit_all { struct type : public virtual first<Seq>::type, public virtual inherit_all::type { }; }; assuming first<> and tail<> exist or are easily implementable. Then template <typename Seq> struct Base_and_Seq : public virtual Base, public virtual inherit_all<Seq>::type { };

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

Does any of that work, or at least head in the right direction? Or am I just recreating what inherit_linearly, etc already does? Tony