//ChangeLog:
//  2011-01-17.1445CST
//    copied from post with headers:
/*
From: Paul <peebor@gmail.com>
Newsgroups: gmane.comp.lib.boost.user
Subject: Re: large variant performance compared (50 elements)
Date: Mon, 17 Jan 2011 21:18:54 +0100
Lines: 66
 */
#include <boost/mpl/vector.hpp>
#include <boost/mpl/is_sequence.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/iteration/local.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/test/minimal.hpp>

#include "CLoPtrVariant.hpp"
#include <boost/shared_ptr.hpp>

  class CVisitBinary
    : public Layout::static_visitor<bool>
  {
  public:
    template<typename T, typename U>
    bool operator()(const T&, const U&) const
    {
      return false;
    }

    template<typename T>
    bool operator()(const T&, const T&) const
    {
      return true;
    }
  };

template<typename Typelist, typename ElementType1, typename ElementType2>
void TestVariantBinary()
{
  typedef typename Layout::make_variant_over<Typelist>::type variant_t;

  variant_t v1_1(boost::shared_ptr<ElementType1>(new ElementType1));
  variant_t v1_2(boost::shared_ptr<ElementType1>(new ElementType1));
  variant_t v2_1(boost::shared_ptr<ElementType2>(new ElementType2));
  BOOST_CHECK(Layout::apply_visitor(CVisitBinary(), v1_1, v1_2)); //Same type
  BOOST_CHECK(Layout::apply_visitor(CVisitBinary(), v1_1, v1_1)); //Same type, same instance
  BOOST_CHECK(!Layout::apply_visitor(CVisitBinary(), v1_1, v2_1)); //Different types
}

//Generate 200 types (class C1, C2, ... C200)
#define BOOST_PP_LOCAL_MACRO(n) \
  class BOOST_PP_CAT(I, n) \
  { \
  public: \
  }; \
  \
  class BOOST_PP_CAT(C, n) \
    : public BOOST_PP_CAT(I, n) \
  { \
  public: \
    int i; \
  };
#define BOOST_PP_LOCAL_LIMITS (0, 200)
#include BOOST_PP_LOCAL_ITERATE()

//Generate mpl sequences
#define SHARED_PTR_C(z, n, data) boost::shared_ptr<BOOST_PP_CAT(C, n)>
#define SHARED_PTR_I(z, n, data) boost::shared_ptr<BOOST_PP_CAT(I, n)>

typedef boost::mpl::vector<BOOST_PP_ENUM(10, SHARED_PTR_C, 0)> MplVectorC10_t;

void test()
{
  TestVariantBinary<MplVectorC10_t, C3, C4>(); //2 phase visitation giving 100 paths
}