C++ type registration at compile time trick

Question

I have the following situation: suppose I have a bunch of types (functors) which I want to register/compile in during compilation, preferably into something like boost::mpl:

Answer 1

You'll never solve the mpl::vector idea. You can't alter template "variables". Remember that template metaprogramming is a PURE functional language. No side effects at all.

As for registering...the macro thing works fine. Define the macro so that it declares and initializes some small global variable with the registration process. Alternatively you can go down the road I did here:

How to force inclusion of "unused" object definitions in a library

Note the fix if you're trying to do it in a library.