| /* Boost.MultiIndex example of use of multi_index_container::ctor_args_list. |
| * |
| * Copyright 2003-2008 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/identity.hpp> |
| #include <boost/multi_index/ordered_index.hpp> |
| #include <algorithm> |
| #include <iostream> |
| #include <iterator> |
| |
| using boost::multi_index_container; |
| using namespace boost::multi_index; |
| |
| /* modulo_less order numbers according to their division residual. |
| * For instance, if modulo==10 then 22 is less than 15 as 22%10==2 and |
| * 15%10==5. |
| */ |
| |
| template<typename IntegralType> |
| struct modulo_less |
| { |
| modulo_less(IntegralType m):modulo(m){} |
| |
| bool operator()(IntegralType x,IntegralType y)const |
| { |
| return (x%modulo)<(y%modulo); |
| } |
| |
| private: |
| IntegralType modulo; |
| }; |
| |
| /* multi_index_container of unsigned ints holding a "natural" index plus |
| * an ordering based on modulo_less. |
| */ |
| |
| typedef multi_index_container< |
| unsigned int, |
| indexed_by< |
| ordered_unique<identity<unsigned int> >, |
| ordered_non_unique<identity<unsigned int>, modulo_less<unsigned int> > |
| > |
| > modulo_indexed_set; |
| |
| int main() |
| { |
| /* define a modulo_indexed_set with modulo==10 */ |
| |
| modulo_indexed_set::ctor_args_list args_list= |
| boost::make_tuple( |
| /* ctor_args for index #0 is default constructible */ |
| nth_index<modulo_indexed_set,0>::type::ctor_args(), |
| |
| /* first parm is key_from_value, second is our sought for key_compare */ |
| boost::make_tuple(identity<unsigned int>(),modulo_less<unsigned int>(10)) |
| ); |
| |
| modulo_indexed_set m(args_list); |
| /* this could have be written online without the args_list variable, |
| * left as it is for explanatory purposes. */ |
| |
| /* insert some numbers */ |
| |
| unsigned int numbers[]={0,1,20,40,33,68,11,101,60,34,88,230,21,4,7,17}; |
| const std::size_t numbers_length(sizeof(numbers)/sizeof(numbers[0])); |
| |
| m.insert(&numbers[0],&numbers[numbers_length]); |
| |
| /* lists all numbers in order, along with their "equivalence class", that is, |
| * the equivalent numbers under modulo_less |
| */ |
| |
| for(modulo_indexed_set::iterator it=m.begin();it!=m.end();++it){ |
| std::cout<<*it<<" -> ( "; |
| |
| nth_index<modulo_indexed_set,1>::type::iterator it0,it1; |
| boost::tie(it0,it1)=get<1>(m).equal_range(*it); |
| std::copy(it0,it1,std::ostream_iterator<unsigned int>(std::cout," ")); |
| |
| std::cout<<")"<<std::endl; |
| } |
| |
| return 0; |
| } |