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// Copyright 2017 Daniel Parker
// Distributed under the Boost license, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// See https://github.com/danielaparker/jsoncons for latest version
#ifndef JSONCONS_ENCODE_TRAITS_HPP
#define JSONCONS_ENCODE_TRAITS_HPP
#include <string>
#include <tuple>
#include <array>
#include <memory>
#include <type_traits> // std::enable_if, std::true_type, std::false_type
#include <jsoncons/json_visitor.hpp>
#include <jsoncons/json_decoder.hpp>
#include <jsoncons/json_options.hpp>
#include <jsoncons/json_encoder.hpp>
#include <jsoncons/json_type_traits.hpp>
#include <jsoncons/conv_error.hpp>
namespace jsoncons {
// encode_traits
template <class T, class CharT, class Enable = void>
struct encode_traits
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
encode(std::integral_constant<bool, type_traits::is_stateless<typename Json::allocator_type>::value>(),
val, encoder, proto, ec);
}
private:
template <class Json>
static void encode(std::true_type,
const T& val,
basic_json_visitor<CharT>& encoder,
const Json& /*proto*/,
std::error_code& ec)
{
auto j = json_type_traits<Json,T>::to_json(val);
j.dump(encoder, ec);
}
template <class Json>
static void encode(std::false_type,
const T& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
auto j = json_type_traits<Json,T>::to_json(val, proto.get_allocator());
j.dump(encoder, ec);
}
};
// specializations
// bool
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<type_traits::is_bool<T>::value
>::type>
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
encoder.bool_value(val,semantic_tag::none,ser_context(),ec);
}
};
// uint
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<type_traits::is_u8_u16_u32_or_u64<T>::value
>::type>
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
encoder.uint64_value(val,semantic_tag::none,ser_context(),ec);
}
};
// int
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<type_traits::is_i8_i16_i32_or_i64<T>::value
>::type>
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
encoder.int64_value(val,semantic_tag::none,ser_context(),ec);
}
};
// float or double
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<type_traits::is_float_or_double<T>::value
>::type>
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
encoder.double_value(val,semantic_tag::none,ser_context(),ec);
}
};
// string
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<type_traits::is_basic_string<T>::value &&
std::is_same<typename T::value_type,CharT>::value
>::type>
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
encoder.string_value(val,semantic_tag::none,ser_context(),ec);
}
};
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<type_traits::is_basic_string<T>::value &&
!std::is_same<typename T::value_type,CharT>::value
>::type>
{
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
std::basic_string<CharT> s;
unicode_traits::convert(val.data(), val.size(), s);
encoder.string_value(s,semantic_tag::none,ser_context(),ec);
}
};
// std::pair
template <class T1, class T2, class CharT>
struct encode_traits<std::pair<T1, T2>, CharT>
{
using value_type = std::pair<T1, T2>;
template <class Json>
static void encode(const value_type& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
encoder.begin_array(2,semantic_tag::none,ser_context(),ec);
if (ec) return;
encode_traits<T1,CharT>::encode(val.first, encoder, proto, ec);
if (ec) return;
encode_traits<T2,CharT>::encode(val.second, encoder, proto, ec);
if (ec) return;
encoder.end_array(ser_context(),ec);
}
};
// std::tuple
namespace detail
{
template<size_t Pos, std::size_t Size, class Json, class Tuple>
struct json_serialize_tuple_helper
{
using char_type = typename Json::char_type;
using element_type = typename std::tuple_element<Size-Pos, Tuple>::type;
using next = json_serialize_tuple_helper<Pos-1, Size, Json, Tuple>;
static void encode(const Tuple& tuple,
basic_json_visitor<char_type>& encoder,
const Json& proto,
std::error_code& ec)
{
encode_traits<element_type,char_type>::encode(std::get<Size-Pos>(tuple), encoder, proto, ec);
if (ec) return;
next::encode(tuple, encoder, proto, ec);
}
};
template<size_t Size, class Json, class Tuple>
struct json_serialize_tuple_helper<0, Size, Json, Tuple>
{
using char_type = typename Json::char_type;
static void encode(const Tuple&,
basic_json_visitor<char_type>&,
const Json&,
std::error_code&)
{
}
};
} // namespace detail
template <class CharT, typename... E>
struct encode_traits<std::tuple<E...>, CharT>
{
using value_type = std::tuple<E...>;
static constexpr std::size_t size = sizeof...(E);
template <class Json>
static void encode(const value_type& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
using helper = jsoncons::detail::json_serialize_tuple_helper<size, size, Json, std::tuple<E...>>;
encoder.begin_array(size,semantic_tag::none,ser_context(),ec);
if (ec) return;
helper::encode(val, encoder, proto, ec);
if (ec) return;
encoder.end_array(ser_context(),ec);
}
};
// vector like
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<!is_json_type_traits_declared<T>::value &&
type_traits::is_list_like<T>::value &&
!type_traits::is_typed_array<T>::value
>::type>
{
using value_type = typename T::value_type;
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
encoder.begin_array(val.size(),semantic_tag::none,ser_context(),ec);
if (ec) return;
for (auto it = std::begin(val); it != std::end(val); ++it)
{
encode_traits<value_type,CharT>::encode(*it, encoder, proto, ec);
if (ec) return;
}
encoder.end_array(ser_context(), ec);
}
};
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<!is_json_type_traits_declared<T>::value &&
type_traits::is_list_like<T>::value &&
type_traits::is_typed_array<T>::value
>::type>
{
using value_type = typename T::value_type;
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json&,
std::error_code& ec)
{
encoder.typed_array(jsoncons::span<const value_type>(val), semantic_tag::none, ser_context(), ec);
}
};
// std::array
template <class T, class CharT, std::size_t N>
struct encode_traits<std::array<T,N>,CharT>
{
using value_type = typename std::array<T,N>::value_type;
template <class Json>
static void encode(const std::array<T, N>& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
encoder.begin_array(val.size(),semantic_tag::none,ser_context(),ec);
if (ec) return;
for (auto it = std::begin(val); it != std::end(val); ++it)
{
encode_traits<value_type,CharT>::encode(*it, encoder, proto, ec);
if (ec) return;
}
encoder.end_array(ser_context(),ec);
}
};
// map like
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<!is_json_type_traits_declared<T>::value &&
type_traits::is_map_like<T>::value &&
type_traits::is_constructible_from_const_pointer_and_size<typename T::key_type>::value
>::type>
{
using mapped_type = typename T::mapped_type;
using value_type = typename T::value_type;
using key_type = typename T::key_type;
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
encoder.begin_object(val.size(), semantic_tag::none, ser_context(), ec);
if (ec) return;
for (auto it = std::begin(val); it != std::end(val); ++it)
{
encoder.key(it->first);
encode_traits<mapped_type,CharT>::encode(it->second, encoder, proto, ec);
if (ec) return;
}
encoder.end_object(ser_context(), ec);
if (ec) return;
}
};
template <class T, class CharT>
struct encode_traits<T,CharT,
typename std::enable_if<!is_json_type_traits_declared<T>::value &&
type_traits::is_map_like<T>::value &&
std::is_integral<typename T::key_type>::value
>::type>
{
using mapped_type = typename T::mapped_type;
using value_type = typename T::value_type;
using key_type = typename T::key_type;
template <class Json>
static void encode(const T& val,
basic_json_visitor<CharT>& encoder,
const Json& proto,
std::error_code& ec)
{
encoder.begin_object(val.size(), semantic_tag::none, ser_context(), ec);
if (ec) return;
for (auto it = std::begin(val); it != std::end(val); ++it)
{
std::basic_string<typename Json::char_type> s;
jsoncons::detail::from_integer(it->first,s);
encoder.key(s);
encode_traits<mapped_type,CharT>::encode(it->second, encoder, proto, ec);
if (ec) return;
}
encoder.end_object(ser_context(), ec);
if (ec) return;
}
};
} // jsoncons
#endif
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