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

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga  2015-2015
   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_map_code
  13 #include <boost/static_assert.hpp>
  14 #include <boost/type_traits/is_same.hpp>
  15 #include <boost/intrusive/set.hpp>
  16 #include <boost/intrusive/unordered_set.hpp>
  17 #include <vector>
  18 #include <cassert>
  19
  20 using namespace boost::intrusive;
  21
  22 class MyClass : public set_base_hook<>
  23               , public unordered_set_base_hook<>
  24 {
  25    public:
  26    int first;
  27    explicit MyClass(int i) : first(i){}
  28 };
  29
  30 //key_of_value function object, must:
  31 //- be default constructible if the container constructor requires it
  32 //- define the key type using "type"
  33 //- define an operator() taking "const value_type&" and
  34 //    returning "type" or "const type &"
  35 struct first_int_is_key
  36 {
  37    typedef int type;
  38
  39    const type & operator()(const MyClass& v) const
  40    {  return v.first;  }
  41 };
  42
  43 //Define omap like ordered and unordered classes
  44 typedef set< MyClass, key_of_value<first_int_is_key> > OrderedMap;
  45 typedef unordered_set< MyClass, key_of_value<first_int_is_key> > UnorderedMap;
  46
  47 int main()
  48 {
  49    BOOST_STATIC_ASSERT((boost::is_same<  OrderedMap::key_type, int>::value));
  50    BOOST_STATIC_ASSERT((boost::is_same<UnorderedMap::key_type, int>::value));
  51
  52    //Create several MyClass objects, each one with a different value
  53    //and insert them into the omap
  54    std::vector<MyClass> values;
  55    for(int i = 0; i < 100; ++i)  values.push_back(MyClass(i));
  56
  57    //Create ordered/unordered maps and insert values
  58    OrderedMap   omap(values.begin(), values.end());
  59    UnorderedMap::bucket_type buckets[100];
  60    UnorderedMap umap(values.begin(), values.end(), UnorderedMap::bucket_traits(buckets, 100));
  61
  62    //Test each element using the key_type (int)
  63    for(int i = 0; i != 100; ++i){
  64       assert(omap.find(i) != omap.end());
  65       assert(umap.find(i) != umap.end());
  66       assert(omap.lower_bound(i) != omap.end());
  67       assert(++omap.lower_bound(i) == omap.upper_bound(i));
  68       assert(omap.equal_range(i).first != omap.equal_range(i).second);
  69       assert(umap.equal_range(i).first != umap.equal_range(i).second);
  70    }
  71
  72    //Count and erase by key
  73    for(int i = 0; i != 100; ++i){
  74       assert(1 == omap.count(i));
  75       assert(1 == umap.count(i));
  76       assert(1 == omap.erase(i));
  77       assert(1 == umap.erase(i));
  78    }
  79    assert(omap.empty());
  80    assert(umap.empty());
  81
  82    return 0;
  83 }
  84 //]