text: // Copyright (c) 2014-2018, The Monero Project
  //
  // All rights reserved.
  //
  // Redistribution and use in source and binary forms, with or without modification, are
  // permitted provided that the following conditions are met:
  //
  // 1. Redistributions of source code must retain the above copyright notice, this list of
  //    conditions and the following disclaimer.
  //
  // 2. Redistributions in binary form must reproduce the above copyright notice, this list
  //    of conditions and the following disclaimer in the documentation and/or other
  //    materials provided with the distribution.
  //
  // 3. Neither the name of the copyright holder nor the names of its contributors may be
  //    used to endorse or promote products derived from this software without specific
  //    prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  //
  // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
  
  #include <cstddef>
  #include <ios>
  #include <iostream>
  #include <type_traits>
  #include <vector>
  
  inline bool hexdecode(const char *from, std::size_t length, void *to)
  {
  	std::size_t i;
  	for(i = 0; i < length; i++)
  	{
  		int v = 0;
  		if(from[2 * i] >= '0' && from[2 * i] <= '9')
  		{
  			v = from[2 * i] - '0';
  		}
  		else if(from[2 * i] >= 'a' && from[2 * i] <= 'f')
  		{
  			v = from[2 * i] - 'a' + 10;
  		}
  		else
  		{
  			return false;
  		}
  		v <<= 4;
  		if(from[2 * i + 1] >= '0' && from[2 * i + 1] <= '9')
  		{
  			v |= from[2 * i + 1] - '0';
  		}
  		else if(from[2 * i + 1] >= 'a' && from[2 * i + 1] <= 'f')
  		{
  			v |= from[2 * i + 1] - 'a' + 10;
  		}
  		else
  		{
  			return false;
  		}
  		*(reinterpret_cast<unsigned char *>(to) + i) = v;
  	}
  	return true;
  }
  
  inline void get(std::istream &input, bool &res)
  {
  	std::string sres;
  	input >> sres;
  	if(sres == "false")
  	{
  		res = false;
  	}
  	else if(sres == "true")
  	{
  		res = true;
  	}
  	else
  	{
  		input.setstate(std::ios_base::failbit);
  	}
  }
  
  template <typename T>
  typename std::enable_if<std::is_integral<T>::value, void>::type
  get(std::istream &input, T &res)
  {
  	input >> res;
  }
  
  inline void getvar(std::istream &input, std::size_t length, void *res)
  {
  	std::string sres;
  	input >> sres;
  	if(sres.length() != 2 * length || !hexdecode(sres.data(), length, res))
  	{
  		input.setstate(std::ios_base::failbit);
  	}
  }
  
  template <typename T>
  typename std::enable_if<std::is_standard_layout<T>::value && !std::is_scalar<T>::value, void>::type
  get(std::istream &input, T &res)
  {
  	getvar(input, sizeof(T), &res);
  }
  
  inline void get(std::istream &input, std::vector<char> &res)
  {
  	std::string sres;
  	input >> sres;
  	if(sres == "x")
  	{
  		res.clear();
  	}
  	else if(sres.length() % 2 != 0)
  	{
  		input.setstate(std::ios_base::failbit);
  	}
  	else
  	{
  		std::size_t length = sres.length() / 2;
  		res.resize(length);
  		if(!hexdecode(sres.data(), length, res.data()))
  		{
  			input.setstate(std::ios_base::failbit);
  		}
  	}
  }
  
  #if !defined(_MSC_VER) || _MSC_VER >= 1800
  
  template <typename T, typename... TT>
  typename std::enable_if<(sizeof...(TT) > 0), void>::type
  get(std::istream &input, T &res, TT &... resres)
  {
  	get(input, res);
  	get(input, resres...);
  }
  
  #else
  #include <boost/preprocessor/cat.hpp>
  #include <boost/preprocessor/repetition/enum_binary_params.hpp>
  #include <boost/preprocessor/repetition/enum_params.hpp>
  #include <boost/preprocessor/repetition/repeat.hpp>
  #include <boost/preprocessor/repetition/repeat_from_to.hpp>
  
  #define NESTED_GET(z, n, data) get(input, BOOST_PP_CAT(res, n));
  #define GET(z, n, data)                                                    \
  	template <BOOST_PP_ENUM_PARAMS(n, typename T)>                         \
  	void get(std::istream &input, BOOST_PP_ENUM_BINARY_PARAMS(n, T, &res)) \
  	{                                                                      \
  		BOOST_PP_REPEAT(n, NESTED_GET, ~)                                  \
  	}
  BOOST_PP_REPEAT_FROM_TO(2, 5, GET, ~)
  
  #endif
  