I have a struct to store info about persons and multi_index_contaider to store such objects. Mult-index uses for search by different criteria.
I've added several persons into container and want to find person by lastname. It works great, if I use whole lastname. But it returns nothig if I try to find person by a part of a lastname (first letters of a lastname).
As you know, partial string search works as a charm for std::set<string
>. So I've only wraped strings by a struct and lost that functionality.
Here is compilable code:
#include <iostream>
#include <string>
#include <algorithm>
#include <set>
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/identity.hpp>
#include <boost/multi_index/member.hpp>
#include <boost/multi_index/composite_key.hpp>
#define DEFAULT_ADDRESS "Moscow"
#define DEFAULT_PHONE "11223344"
typedef unsigned int uint;
using namespace boost;
using namespace boost::multi_index;
struct person
{
std::string m_first_name;
std::string m_last_name;
std::string m_third_name;
std::string m_address;
std::string m_phone;
person();
person(std::string f, std::string l, std::string t = "", std::string a = DEFAULT_ADDRESS, std::string p = DEFAULT_PHONE) :
m_first_name(f), m_last_name(l), m_third_name(t), m_address(a),
m_phone(p) { }
virtual ~person()
{ /*std::cout << "Destructing person..." << std::endl;*/ }
person& operator=(const person& rhs);
};
typedef multi_index_container<
person,
indexed_by<
ordered_unique<identity<person> >,
ordered_non_unique<
composite_key<
person,
member<person, std::string, &person::m_last_name>,
member<person, std::string, &person::m_first_name>,
member<person, std::string, &person::m_third_name>
>
>
>
> persons_set;
person& person::operator=(const person &rhs)
{
m_first_name = rhs.m_first_name;
m_last_name = rhs.m_last_name;
m_third_name = rhs.m_third_name;
m_address = rhs.m_address;
m_phone = rhs.m_phone;
return *this;
}
bool operator<(const person &lhs, const person &rhs)
{
if(lhs.m_last_name == rhs.m_last_name)
{
if(lhs.m_first_name == rhs.m_first_name)
return (lhs.m_third_name < rhs.m_third_name);
return (lhs.m_first_name < rhs.m_first_name);
}
return (lhs.m_last_name < rhs.m_last_name);
}
std::ostream& operator<<(std::ostream &s, const person &rhs)
{
s << "Person's last name: " << rhs.m_last_name << std::endl;
s << "Person's name: " << rhs.m_first_name << std::endl;
if (!rhs.m_third_name.empty())
s << "Person's third name: " << rhs.m_third_name << std::endl;
s << "Phone: " << rhs.m_phone << std::endl;
s << "Address: " << rhs.m_address << std::endl << std::endl;
return s;
}
struct comp_persons
{
bool operator()( const person& p1, const person& p2) const
{
if (p2.m_last_name.empty()) return false;
return ( p1.m_last_name.find(p2.m_last_name) == 0 );
}
};
int main()
{
persons_set my_set;
persons_set::nth_index<0>::type &general_index = my_set.get<0>(); // shortcut to the 1st index
persons_set::nth_index<1>::type &names_index = my_set.get<1>(); // shortcut to the 2nd index
// adding persons
general_index.insert(person("Alex", "Johnson", "Somename"));
general_index.insert(person("Alex", "Goodspeed"));
general_index.insert(person("Peter", "Goodspeed"));
general_index.insert(person("Akira", "Kurosava"));
// search via 2nd index (based on last_name)
std::pair<persons_set::nth_index<1>::type::const_iterator, persons_set::nth_index<1>::type::const_iterator>
n_it = names_index.equal_range("Goodspeed");
// this finds nothing
/*std::pair<persons_set::nth_index<1>::type::const_iterator, persons_set::nth_index<1>::type::const_iterator>
n_it = names_index.equal_range("Goodspe");*/
// idea by Kirill V. Lyadvinsky. This code crashes on the start.
// I guess because behaviour of comp_persons differs from default less<> or reloaded operator <
/*std::pair<persons_set::nth_index<1>::type::const_iterator, persons_set::nth_index<1>::type::const_iterator>
n_it = std::equal_range(names_index.begin(), names_index.end(), person("Alex", "Goodspe"), comp_persons());*/
std::copy( n_it.first ,n_it.second,
std::ostream_iterator<person>(std::cout));
return 0;
}