1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
/* Boost.MultiIndex basic example.
*
* Copyright 2003-2013 Joaquin M Lopez Munoz.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*
* See http://www.boost.org/libs/multi_index for library home page.
*/
#if !defined(NDEBUG)
#define BOOST_MULTI_INDEX_ENABLE_INVARIANT_CHECKING
#define BOOST_MULTI_INDEX_ENABLE_SAFE_MODE
#endif
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/member.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <string>
using boost::multi_index_container;
using namespace boost::multi_index;
/* an employee record holds its ID, name and age */
struct employee
{
int id;
std::string name;
int age;
employee(int id_,std::string name_,int age_):id(id_),name(name_),age(age_){}
friend std::ostream& operator<<(std::ostream& os,const employee& e)
{
os<<e.id<<" "<<e.name<<" "<<e.age<<std::endl;
return os;
}
};
/* tags for accessing the corresponding indices of employee_set */
struct id{};
struct name{};
struct age{};
/* see Compiler specifics: Use of member_offset for info on
* BOOST_MULTI_INDEX_MEMBER
*/
/* Define a multi_index_container of employees with following indices:
* - a unique index sorted by employee::int,
* - a non-unique index sorted by employee::name,
* - a non-unique index sorted by employee::age.
*/
typedef multi_index_container<
employee,
indexed_by<
ordered_unique<
tag<id>, BOOST_MULTI_INDEX_MEMBER(employee,int,id)>,
ordered_non_unique<
tag<name>,BOOST_MULTI_INDEX_MEMBER(employee,std::string,name)>,
ordered_non_unique<
tag<age>, BOOST_MULTI_INDEX_MEMBER(employee,int,age)> >
> employee_set;
template<typename Tag,typename MultiIndexContainer>
void print_out_by(const MultiIndexContainer& s)
{
/* obtain a reference to the index tagged by Tag */
const typename boost::multi_index::index<MultiIndexContainer,Tag>::type& i=
get<Tag>(s);
typedef typename MultiIndexContainer::value_type value_type;
/* dump the elements of the index to cout */
std::copy(i.begin(),i.end(),std::ostream_iterator<value_type>(std::cout));
}
int main()
{
employee_set es;
es.insert(employee(0,"Joe",31));
es.insert(employee(1,"Robert",27));
es.insert(employee(2,"John",40));
/* next insertion will fail, as there is an employee with
* the same ID
*/
es.insert(employee(2,"Aristotle",2387));
es.insert(employee(3,"Albert",20));
es.insert(employee(4,"John",57));
/* list the employees sorted by ID, name and age */
std::cout<<"by ID"<<std::endl;
print_out_by<id>(es);
std::cout<<std::endl;
std::cout<<"by name"<<std::endl;
print_out_by<name>(es);
std::cout<<std::endl;
std::cout<<"by age"<<std::endl;
print_out_by<age>(es);
std::cout<<std::endl;
return 0;
}
|
