ceph/src/boost/libs/intrusive/example/doc_sg_set.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga  2007-2013
   4 //
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // See http://www.boost.org/libs/intrusive for documentation.
  10 //
  11 /////////////////////////////////////////////////////////////////////////////
  12 //[doc_sg_set_code
  13 #include <boost/intrusive/sg_set.hpp>
  14 #include <vector>
  15 #include <functional>
  16 #include <cassert>
  17
  18 using namespace boost::intrusive;
  19
  20 class MyClass : public bs_set_base_hook<>
  21 {
  22    int int_;
  23
  24    public:
  25    //This is a member hook
  26    bs_set_member_hook<> member_hook_;
  27
  28    MyClass(int i)
  29       :  int_(i)
  30       {}
  31    friend bool operator< (const MyClass &a, const MyClass &b)
  32       {  return a.int_ < b.int_;  }
  33    friend bool operator> (const MyClass &a, const MyClass &b)
  34       {  return a.int_ > b.int_;  }
  35    friend bool operator== (const MyClass &a, const MyClass &b)
  36       {  return a.int_ == b.int_;  }
  37 };
  38
  39 //Define an sg_set using the base hook that will store values in reverse order
  40 //and won't execute floating point operations.
  41 typedef sg_set
  42    < MyClass, compare<std::greater<MyClass> >, floating_point<false> >   BaseSet;
  43
  44 //Define an multiset using the member hook
  45 typedef member_hook<MyClass, bs_set_member_hook<>, &MyClass::member_hook_> MemberOption;
  46 typedef sg_multiset< MyClass, MemberOption>   MemberMultiset;
  47
  48 int main()
  49 {
  50    typedef std::vector<MyClass>::iterator VectIt;
  51
  52    //Create several MyClass objects, each one with a different value
  53    std::vector<MyClass> values;
  54    for(int i = 0; i < 100; ++i)  values.push_back(MyClass(i));
  55
  56    BaseSet baseset;
  57    MemberMultiset membermultiset;
  58
  59    //Now insert them in the reverse order in the base hook sg_set
  60    for(VectIt it(values.begin()), itend(values.end()); it != itend; ++it){
  61       baseset.insert(*it);
  62       membermultiset.insert(*it);
  63    }
  64
  65    //Change balance factor
  66    membermultiset.balance_factor(0.9f);
  67
  68    //Now test sg_sets
  69    {
  70       BaseSet::reverse_iterator rbit(baseset.rbegin());
  71       MemberMultiset::iterator mit(membermultiset.begin());
  72       VectIt it(values.begin()), itend(values.end());
  73
  74       //Test the objects inserted in the base hook sg_set
  75       for(; it != itend; ++it, ++rbit)
  76          if(&*rbit != &*it)   return 1;
  77
  78       //Test the objects inserted in the member hook sg_set
  79       for(it = values.begin(); it != itend; ++it, ++mit)
  80          if(&*mit != &*it) return 1;
  81    }
  82    return 0;
  83 }
  84 //]