stream_tuple.h

/*****************************************************************************
* Multiscale Universal Interface Code Coupling Library                       *
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* Copyright (C) 2019 Y. H. Tang, S. Kudo, X. Bian, Z. Li, G. E. Karniadakis  *
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/**
 * @file stream_tuple.h
 * @author S. Kudo
 * @date 26 March 2014
 * @brief Defines the stream in/out for std::tuple data type.
 *
 * The order of elements in stream-in/out is first-argument to last-argument.
 */

#ifndef MUI_STREAM_TUPLE_H
#define MUI_STREAM_TUPLE_H

#include <tuple>

#include "stream.h"

namespace mui {

// build integer sequence 0, 1, ... in compile time
template<std::size_t... indexes>
struct index_sequence {
	typedef index_sequence<indexes...,sizeof...(indexes)> next;
};
template<std::size_t N>
struct make_index_sequence {
	typedef typename make_index_sequence<N-1>::type::next type;
};
template<>
struct make_index_sequence<0>{
	typedef index_sequence<> type;
};


namespace {
template<std::size_t N, std::size_t MAX, typename... Args>
struct input_tuple_impl_ {
	static void apply( istream& stream, std::tuple<Args...>& t){
		stream >> std::get<N>(t);
		input_tuple_impl_<N+1,MAX,Args...>::apply(stream,t);
	}
};
template<std::size_t N, typename... Args>
struct input_tuple_impl_<N,N,Args...> {
	static void apply( istream& , std::tuple<Args...>& ){}
};
}

template<typename... Args>
inline istream& operator>> ( istream& stream, std::tuple<Args...>& ret )
{
	std::tuple<Args...> t;
	input_tuple_impl_<0,sizeof...(Args),Args...>::apply(stream,t);
	ret.swap(t);
	return stream;
}


namespace{
template<std::size_t N, std::size_t MAX, typename... Args>
struct output_tuple_impl_ {
	static void apply( ostream& stream, const std::tuple<Args...>& t){
		stream << std::get<N>(t);
		output_tuple_impl_<N+1,MAX,Args...>::apply(stream,t);
	}
};
template<std::size_t N, typename... Args>
struct output_tuple_impl_<N,N,Args...> {
	static void apply( ostream& , const std::tuple<Args...>& ){}
};
}

template<typename... Args>
inline ostream& operator<< ( ostream& stream, const std::tuple<Args...>& t )
{
	output_tuple_impl_<0,sizeof...(Args),Args...>::apply(stream,t);
	return stream;
}

}

#endif