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- /* 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;
- }
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