[boost] Empty Base Optimization

From: Beman Dawes (beman_at_[hidden])
Date: 1999-11-18 21:06:46

Howard Hinnant and Greg Colvin have suggested we include Nathan
Myer's empty base optimization in boost/utility.hpp.  Seems quite
useful to me, too.

If you are not familiar with this optimization, check out
http://www.cantrip.org/emptyopt.html

Greg suggested sticking with Nathat's code (except for changing the
name from BaseOpt, to match Boost practice):

  template <typename Base, typename Member>
  struct base_opt : Base {
      Member m;
      base_opt(Base const& b, Member const& m)
          : Base(b), m(m) {}
  };

My preference would be for more descriptive names, like
"empty_base_optimization" and "member".

Anyone out there care to write some brief documentation?  Nathan?

--Beman