polynomial.hpp

// Copyright plasma-effect 2014.
// 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)

#pragma once

#include<vector>
#include<utility>
#include<algorithm>
#include<type_traits>

namespace plasma
{
	template<std::size_t... Is>struct index_tuple{};
	namespace detail
	{
		template<std::size_t, class, bool>struct index_count_impl;
		template<std::size_t N, std::size_t... Is>
			struct index_count_impl < N, index_tuple<Is...>, true >
		{
			typedef index_tuple<Is..., (Is + N)..., 2 * N> type;
		};
		template<std::size_t N, std::size_t... Is>
			struct index_count_impl < N, index_tuple<Is...>, false >
		{
			typedef index_tuple<Is..., (Is + N)...> type;
		};
	}
	template<std::size_t N>struct index_count
	{
		typedef typename detail::index_count_impl <
			N / 2, typename index_count<N / 2>::type, N % 2 > ::type type;
	};
	template<>struct index_count < 0 >
	{
		typedef index_tuple<> type;
	};
	template<std::size_t N>typename index_count<N>::type make_index_count()
	{
		return typename index_count<N>::type();
	}

	template<class>struct sfinae_helper
	{
		typedef void type;
	};

	template<class T>struct polynomial
	{
		std::size_t deg_;
		std::vector<T> coefficient_;
		
		//default construct
		polynomial() :deg_(0), coefficient_(){}
		
		//iterator
		template<class InputIterator>
		polynomial(InputIterator beg, InputIterator end)
			: deg_(std::distance(beg, end)-1), coefficient_(deg_+1)
		{
			std::move(beg, end, coefficient_.begin());
		}
		
		template<std::size_t N, std::size_t... Is>
		polynomial(T const(&ar)[N], index_tuple<Is...>) 
			: deg_(N - 1), coefficient_({ ar[Is]... }){}

		//array
		template<std::size_t N>
			polynomial(T const(&ar)[N]) 
			:polynomial(ar, make_index_count<N>()){}
	};	
}