multiset extensions

alib2std/src/alib/multiset

+#include <extensions/container/multiset.hpp>

alib2std/src/extensions/container/multiset.hpp

+/*
+ * multiset.hpp
+ *
+ * This file is part of Algorithms library toolkit.
+ * Copyright (C) 2017 Jan Travnicek (jan.travnicek@fit.cvut.cz)
+
+ * Algorithms library toolkit is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+
+ * Algorithms library toolkit is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with Algorithms library toolkit.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Created on: Apr 1, 2013
+ * Author: Jan Travnicek
+ */
+
+#ifndef __MULTI_SET_H_
+#define __MULTI_SET_H_
+
+#include <set>
+#include <ostream>
+#include <sstream>
+#include <string>
+
+#include <extensions/compare.hpp>
+#include <extensions/range.hpp>
+
+namespace ext {
+
+/**
+ * Class extending the multiset class from the standard library. Original reason is to allow printing of the container with overloaded operator <<.
+ *
+ * The class mimics the behavior of the multiset from the standatd library.
+ *
+ * \tparam T the type of keys inside the multiset
+ * \tparam Cmp the comparator type used to order keys
+ * \tparam Alloc the allocator of values of type T
+ */
+template < typename T, typename Cmp = std::less < >, typename Alloc = std::allocator < T > >
+class multiset : public std::multiset < T, Cmp, Alloc > {
+public:
+	/**
+	 * Inherit constructors of the standard multiset
+	 */
+	using std::multiset < T, Cmp, Alloc >::multiset; // NOLINT(modernize-use-equals-default)
+
+	/**
+	 * Inherit operator = of the standard multiset
+	 */
+	using std::multiset < T, Cmp, Alloc >::operator =;
+#ifndef __clang__
+
+	/**
+	 * Default constructor needed by g++ since it is not inherited
+	 */
+	multiset ( ) = default;
+
+	/**
+	 * Copy constructor needed by g++ since it is not inherited
+	 */
+	multiset ( const multiset & other ) = default;
+
+	/**
+	 * Move constructor needed by g++ since it is not inherited
+	 */
+	multiset ( multiset && other ) = default;
+
+	/**
+	 * Copy operator = needed by g++ since it is not inherited
+	 */
+	multiset & operator = ( multiset && other ) = default;
+
+	/**
+	 * Move operator = needed by g++ since it is not inherited
+	 */
+	multiset & operator = ( const multiset & other ) = default;
+#endif
+	/**
+	 * Constructor from range of values.
+	 *
+	 * \tparam Iterator the type of range iterator
+	 *
+	 * \param range the source range
+	 */
+	template < class Iterator >
+	explicit multiset ( const ext::iterator_range < Iterator > & range ) : multiset ( range.begin ( ), range.end ( ) ) {
+	}
+
+	/**
+	 * \brief
+	 * Inherited behavior of begin for non-const instance.
+	 *
+	 * \return iterator the first element of multiset
+	 */
+	auto begin ( ) & {
+		return std::multiset < T, Cmp, Alloc >::begin ( );
+	}
+
+	/**
+	 * \brief
+	 * Inherited behavior of begin for const instance.
+	 *
+	 * \return const_iterator the first element of multiset
+	 */
+	auto begin ( ) const & {
+		return std::multiset < T, Cmp, Alloc >::begin ( );
+	}
+
+	/**
+	 * \brief
+	 * New variant of begin for rvalues.
+	 *
+	 * \return move_iterator the first element of multiset
+	 */
+	auto begin ( ) && {
+		return make_set_move_iterator ( this->begin ( ) );
+	}
+
+	/**
+	 * \brief
+	 * Inherited behavior of end for non-const instance.
+	 *
+	 * \return iterator to one after the last element of multiset
+	 */
+	auto end ( ) & {
+		return std::multiset < T, Cmp, Alloc >::end ( );
+	}
+
+	/**
+	 * \brief
+	 * Inherited behavior of end for const instance.
+	 *
+	 * \return const_iterator to one after the last element of multiset
+	 */
+	auto end ( ) const & {
+		return std::multiset < T, Cmp, Alloc >::end ( );
+	}
+
+	/**
+	 * \brief
+	 * New variant of end for rvalues.
+	 *
+	 * \return move_iterator to one after the last element of multiset
+	 */
+	auto end ( ) && {
+		return make_set_move_iterator ( this->end ( ) );
+	}
+
+	/**
+	 * \brief
+	 * Make range of non-const begin to end iterators.
+	 *
+	 * \return full range over container values
+	 */
+	auto range ( ) & {
+		auto endIter = end ( );
+		auto beginIter = begin ( );
+		return ext::iterator_range < decltype ( endIter ) > ( beginIter, endIter );
+	}
+
+	/**
+	 * \brief
+	 * Make range of non-const begin to end iterators.
+	 *
+	 * \return full range over container values
+	 */
+	auto range ( ) const & {
+		auto endIter = end ( );
+		auto beginIter = begin ( );
+		return ext::iterator_range < decltype ( endIter ) > ( beginIter, endIter );
+	}
+
+	/**
+	 * \brief
+	 * Make range of move begin to end iterators.
+	 *
+	 * \return full range over container values
+	 */
+	auto range ( ) && {
+		auto endIter = std::move ( * this ).end ( );
+		auto beginIter = std::move ( * this ).begin ( );
+		return ext::iterator_range < decltype ( endIter ) > ( beginIter, endIter );
+	}
+
+	/**
+	 * \brief
+	 * Make range of elements with key equal to the @p key.
+	 *
+	 * \tparam K the key used in the query
+	 *
+	 * \param key the value used in the query
+	 *
+	 * \return selected range of elements
+	 */
+	template < class K >
+	auto equal_range ( K && key ) const & {
+		auto res = std::multiset < T, Cmp, Alloc >::equal_range ( std::forward < K > ( key ) );
+		return ext::iterator_range < decltype ( res.first ) > ( res.first, res.second );
+	}
+
+	/**
+	 * \brief
+	 * Make range of elements with key equal to the @p key.
+	 *
+	 * \tparam K the key used in the query
+	 *
+	 * \param key the value used in the query
+	 *
+	 * \return selected range of elements
+	 */
+	template < class K >
+	auto equal_range ( K && key ) & {
+		auto res = std::multiset < T, Cmp, Alloc >::equal_range ( std::forward < K > ( key ) );
+		return ext::iterator_range < decltype ( res.first ) > ( res.first, res.second );
+	}
+
+	/**
+	 * \brief
+	 * Make range of elements with key equal to the @p key.
+	 *
+	 * \tparam K the key used in the query
+	 *
+	 * \param key the value used in the query
+	 *
+	 * \return selected range of elements
+	 */
+	template < class K >
+	auto equal_range ( K && key ) && {
+		auto res = std::multiset < T, Cmp, Alloc >::equal_range ( std::forward < K > ( key ) );
+		return ext::make_iterator_range ( make_set_move_iterator < T > ( res.first ), make_set_move_iterator < T > ( res.second ) );
+	}
+
+	/**
+	 * \brief
+	 * Test whether the multiset contains a given key
+	 *
+	 * \param key the tested key
+	 *
+	 * \return true if the multiset contains the key, false otherwise
+	 */
+	bool contains ( const T & key ) const { // TODO remove after switching C++20
+		return this->count ( key ) != 0U;
+	}
+
+	/**
+	 * \brief
+	 * Test whether the multiset contains a given key
+	 *
+	 * \tparam K the type of the key
+	 *
+	 * \param key the tested key
+	 *
+	 * \return true if the multiset contains the key, false otherwise
+	 */
+	template < class K >
+	bool contains ( const K & key ) const { // TODO remove after switching C++20
+		return this->count ( key ) != 0U;
+	}
+};
+
+/**
+ * \brief
+ * Operator to print the multiset to the output stream.
+ *
+ * \param out the output stream
+ * \param multiset the multiset to print
+ *
+ * \tparam T the type of keys inside the multiset
+ * \tparam R the type of values inside the multiset
+ * \tparam Ts ... remaining unimportant template parameters of the multiset
+ *
+ * \return the output stream from the \p out
+ */
+template< class T, class ... Ts >
+std::ostream& operator<<(std::ostream& out, const ext::multiset<T, Ts ...>& list) {
+	out << "{";
+
+	bool first = true;
+	for(const T& item : list) {
+		if(!first) out << ", ";
+		first = false;
+		out << item;
+	}
+
+	out << "}";
+	return out;
+}
+
+/**
+ * \brief
+ * Specialisation of the compare structure implementing the three-way comparison.
+ *
+ * \tparam T the type of keys inside the multiset
+ * \tparam R the type of values inside the multiset
+ * \tparam Ts ... remaining unimportant template parameters of the multiset
+ */
+template<class T, class ... Ts>
+struct compare < ext::multiset < T, Ts ... > > {
+
+	/**
+	 * \brief
+	 * Implementation of the three-way comparison.
+	 *
+	 * \param first the left operand of the comparison
+	 * \param second the right operand of the comparison
+	 *
+	 * \return negative value of left < right, positive value if left > right, zero if left == right
+	 */
+	int operator()(const ext::multiset<T, Ts ...>& first, const ext::multiset<T, Ts ...>& second) const {
+		if(first.size() < second.size()) return -1;
+		if(first.size() > second.size()) return 1;
+
+		static compare<typename std::decay < T >::type > comp;
+		for(auto iterF = first.begin(), iterS = second.begin(); iterF != first.end(); ++iterF, ++iterS) {
+			int res = comp(*iterF, *iterS);
+			if(res != 0) return res;
+		}
+		return 0;
+	}
+};
+
+/**
+ * \brief
+ * Overload of to_string function.
+ *
+ * \param value the multiset to be converted to string
+ *
+ * \tparam T the type of values inside the multiset
+ * \tparam Ts ... remaining unimportant template parameters of the multiset
+ *
+ * \return string representation
+ */
+template < class T, class ... Ts >
+std::string to_string ( const ext::multiset < T, Ts ... > & value ) {
+	std::stringstream ss;
+	ss << value;
+	return ss.str();
+}
+
+/**
+ * \brief
+ * Implementation of union of two multisets.
+ *
+ * \tparam T the type of values stored in unioned multisets
+ *
+ * \param first the first multiset to union
+ * \param second the second multiset to union
+ *
+ * \return multiset representing union
+ */
+template < class T >
+ext::multiset < T > operator +( const ext::multiset < T > & first, const ext::multiset < T > & second ) {
+	ext::multiset < T > res ( first );
+
+	res.insert ( second.begin ( ), second.end ( ) );
+	return res;
+}
+
+} /* namespace ext */
+
+#endif /* __MULTI_SET_H_ */