// Copyright (c) 2014-2016, 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 /*! \file variant.h * * \brief for dealing with variants * * \detailed Variant: OOP Union */ #pragma once #include <boost/variant/variant.hpp> #include <boost/variant/apply_visitor.hpp> #include <boost/variant/static_visitor.hpp> #include <boost/mpl/empty.hpp> #include <boost/mpl/if.hpp> #include <boost/mpl/front.hpp> #include <boost/mpl/pop_front.hpp> #include "serialization.h" /*! \struct variant_serialization_triats * * \brief used internally to contain a variant's traits/possible types * * \detailed see the macro VARIANT_TAG in serialization.h:140 */ template <class Archive, class T> struct variant_serialization_traits { }; /*! \struct variant_reader * * \brief reads a variant */ template <class Archive, class Variant, class TBegin, class TEnd> struct variant_reader { typedef typename Archive::variant_tag_type variant_tag_type; typedef typename boost::mpl::next<TBegin>::type TNext; typedef typename boost::mpl::deref<TBegin>::type current_type; // A tail recursive inline function.... okay... static inline bool read(Archive &ar, Variant &v, variant_tag_type t) { if(variant_serialization_traits<Archive, current_type>::get_tag() == t) { current_type x; if(!::do_serialize(ar, x)) { ar.stream().setstate(std::ios::failbit); return false; } v = x; } else { // Tail recursive.... but no mutation is going on. Why? return variant_reader<Archive, Variant, TNext, TEnd>::read(ar, v, t); } return true; } }; // This one just fails when you call it.... okay // So the TEnd parameter must be specified/differnt from TBegin template <class Archive, class Variant, class TBegin> struct variant_reader<Archive, Variant, TBegin, TBegin> { typedef typename Archive::variant_tag_type variant_tag_type; static inline bool read(Archive &ar, Variant &v, variant_tag_type t) { ar.stream().setstate(std::ios::failbit); return false; } }; template <template <bool> class Archive, BOOST_VARIANT_ENUM_PARAMS(typename T)> struct serializer<Archive<false>, boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>> { typedef boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> variant_type; typedef typename Archive<false>::variant_tag_type variant_tag_type; typedef typename variant_type::types types; static bool serialize(Archive<false> &ar, variant_type &v) { variant_tag_type t; ar.begin_variant(); ar.read_variant_tag(t); if(!variant_reader<Archive<false>, variant_type, typename boost::mpl::begin<types>::type, typename boost::mpl::end<types>::type>::read(ar, v, t)) { ar.stream().setstate(std::ios::failbit); return false; } ar.end_variant(); return true; } }; template <template <bool> class Archive, BOOST_VARIANT_ENUM_PARAMS(typename T)> struct serializer<Archive<true>, boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>> { typedef boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> variant_type; //typedef typename Archive<true>::variant_tag_type variant_tag_type; struct visitor : public boost::static_visitor<bool> { Archive<true> &ar; visitor(Archive<true> &a) : ar(a) { } template <class T> bool operator ()(T &rv) const { ar.begin_variant(); ar.write_variant_tag(variant_serialization_traits<Archive<true>, T>::get_tag()); if(!::do_serialize(ar, rv)) { ar.stream().setstate(std::ios::failbit); return false; } ar.end_variant(); return true; } }; static bool serialize(Archive<true> &ar, variant_type &v) { return boost::apply_visitor(visitor(ar), v); } };