set, multiset and rbtree share the same hooks. This is an advantage, because the same user type can be inserted first in a multiset and after that in set without changing the definition of the user class.
set, multiset 和 rbtree 共享相同的鉤子。這是一個優點，因為同一個用戶類型可以先被插入到 multiset 中，然後再插入到 set 中，而無需修改用戶類的定義。

template <class ...Options>
class set_base_hook;

template <class ...Options>
class set_member_hook;

set_base_hook and set_member_hook receive the same options explained in the section How to use Boost.Intrusive plus a size optimization option:
set_base_hook 和 set_member_hook 接受在 如何使用 Boost.Intrusive 一節中說明的各種選項，再加一個空間優化選項： 

template <class T, class ...Options>
class set;

template <class T, class ...Options>
class multiset;

template <class T, class ...Options>
class rbtree;

These containers receive the same options explained in the section How to use Boost.Intrusive:
這些容器接受在 如何使用 Boost.Intrusive 一節中說明的選項：

And they also can receive an additional option:
它們還可以接受另一個選項：

Now let's see a small example using both hooks and both containers:
現在我們來看一個使用這些鉤子和容器的小例子：

#include <boost/intrusive/set.hpp>
#include <vector>
#include <algorithm>
#include <cassert>

using namespace boost::intrusive;

                  //This is a base hook optimized for size
class MyClass : public set_base_hook<optimize_size<true> >
{
   int int_;

   public:
   //This is a member hook
   set_member_hook<> member_hook_;

   MyClass(int i)
      :  int_(i)
      {}
   friend bool operator< (const MyClass &a, const MyClass &b)
      {  return a.int_ < b.int_;  }
   friend bool operator> (const MyClass &a, const MyClass &b)
      {  return a.int_ > b.int_;  }
   friend bool operator== (const MyClass &a, const MyClass &b)
      {  return a.int_ < b.int_;  }
};

//Define a set using the base hook that will store values in reverse order
typedef set< MyClass, compare<std::greater<MyClass> > >     BaseSet;

//Define an multiset using the member hook
typedef member_hook<MyClass, set_member_hook<>, &MyClass::member_hook_> MemberOption;
typedef multiset< MyClass, MemberOption>   MemberMultiset;

int main()
{
   typedef std::vector<MyClass>::iterator VectIt;
   typedef std::vector<MyClass>::reverse_iterator VectRit;

   //Create several MyClass objects, each one with a different value
   std::vector<MyClass> values;
   for(int i = 0; i < 100; ++i)  values.push_back(MyClass(i));

   BaseSet baseset;
   MemberMultiset membermultiset;
   
   //Check that size optimization is activated in the base hook 
   assert(sizeof(set_base_hook<optimize_size<true> >) == 3*sizeof(void*));
   //Check that size optimization is deactivated in the member hook 
   assert(sizeof(set_member_hook<>) > 3*sizeof(void*));

   //Now insert them in the reverse order in the base hook set
   for(VectIt it(values.begin()), itend(values.end()); it != itend; ++it){
      baseset.insert(*it);
      membermultiset.insert(*it);
   }

   //Now test sets
   {
      BaseSet::reverse_iterator rbit(baseset.rbegin()), rbitend(baseset.rend());
      MemberMultiset::iterator mit(membermultiset.begin()), mitend(membermultiset.end());
      VectIt it(values.begin()), itend(values.end());

      //Test the objects inserted in the base hook set
      for(; it != itend; ++it, ++rbit)
         if(&*rbit != &*it)   return 1;

      //Test the objects inserted in the member hook set
      for(it = values.begin(); it != itend; ++it, ++mit)
         if(&*mit != &*it) return 1;
   }
   return 0;
}