unorder_map 自定义KEY

1. boost::unorder_map 实现自定义KEY

 1 // boostLibTest.cpp : 定义控制台应用程序的入口点。
 2 //
 3 #include "stdafx.h"
 4 
 5 #include <boost/functional/hash.hpp>
 6 #include <boost/unordered_map.hpp>
 7 #include <iostream>
 8 #include <set>
 9 #include <map>
10 #include <unordered_map>
11 
12 using namespace std;
13 
14     struct Test
15     {
16         int _id;
17         string _name;
18         set<int> _nums;
19 
20         Test(int id, string name, set<int> nums = set<int>()) :
21             _id(id), _name(name), _nums(nums)
22         {
23         }
24     };
25 
26     bool operator==(const Test& ts1, const Test& ts2)
27     {
28         return ts1._id == ts2._id && ts1._name == ts2._name && ts1._nums == ts2._nums;
29     }
30 
31     size_t hash_value(const Test& test)
32     {
33         std::size_t seed = 0;
34         boost::hash_combine(seed, std::hash_value(test._id));
35         boost::hash_combine(seed, std::hash_value(test._name));
36         for (auto& iter : test._nums){
37             boost::hash_combine(seed, std::hash_value(iter));
38         }
39         return seed;
40     }
41 
42 int _tmain(int argc, _TCHAR* argv[])
43 {
44     set<int> sets = {1,2,3,4,5};
45     boost::unordered_map<Test, string> map;
46     map.insert(make_pair(Test(1, "abc", sets), "123"));
47     map.insert(make_pair(Test(2, "def", sets), "234"));
48     map.insert(make_pair(Test(3, "egh", sets), "345"));
49     map.insert(make_pair(Test(4, "ijk", sets), "456"));
50     map.insert(make_pair(Test(5, "lmn", sets), "567"));
51 
52     auto iter = map.find(Test(3, "egh", sets));
53     if (iter != map.end()){
54         cout << "Find !" << endl;
55     }
56     else{
57         cout << "Not Find !" << endl;
58     }
59 
60     getchar();
61     return 0;
62 }

输出结果为： Find !

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2. std::unorder_map 实现自定义KEY

 1 // boostLibTest.cpp : 定义控制台应用程序的入口点。
 2 //
 3 #include "stdafx.h"
 4 
 5 #include <boost/functional/hash.hpp>
 6 #include <boost/unordered_map.hpp>
 7 #include <iostream>
 8 #include <set>
 9 #include <map>
10 #include <unordered_map>
11 
12 using namespace std;
13 
14     struct Test
15     {
16         int _id;
17         string _name;
18         set<int> _nums;
19 
20         Test(int id, string name, set<int> nums = set<int>()) :
21             _id(id), _name(name), _nums(nums)
22         {
23         }
24     };
25 
26     namespace std
27     {
28         template<>
29         struct hash<Test>
30             : public _Bitwise_hash < Test >
31         {   // hash functor for RECT
32         };
33 
34         inline bool operator == (const Test &ts1, const Test &ts2) _NOEXCEPT
35         {
36             return ts1._id == ts2._id && ts1._name == ts2._name && ts1._nums == ts2._nums;
37         }
38     }
39 
40 int _tmain(int argc, _TCHAR* argv[])
41 {
42     set<int> sets = {1,2,3,4,5};
43     std::unordered_map<Test, string> map;
44     map.insert(make_pair(Test(1, "abc", sets), "123"));
45     map.insert(make_pair(Test(2, "def", sets), "234"));
46     map.insert(make_pair(Test(3, "egh", sets), "345"));
47     map.insert(make_pair(Test(4, "ijk", sets), "456"));
48     map.insert(make_pair(Test(5, "lmn", sets), "567"));
49 
50     auto iter = map.find(Test(3, "egh", sets));
51     if (iter != map.end()){
52         cout << "Find !" << endl;
53     }
54     else{
55         cout << "Not Find !" << endl;
56     }
57 
58     getchar();
59     return 0;
60 }

奇怪的地方来了，std的结果有时候是 Find ！有时候是 Not Find ！

没弄明白这个std::unorder_map怎么回事，我自己直接用了boost::unorder_map