yalantinglibs/include/ylt/struct_pack.hpp

714 lines
25 KiB
C++

/*
* Copyright (c) 2023, Alibaba Group Holding Limited;
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <cstdint>
#include <memory>
#include <type_traits>
#include <utility>
#include "struct_pack/alignment.hpp"
#include "struct_pack/calculate_size.hpp"
#include "struct_pack/compatible.hpp"
#include "struct_pack/derived_helper.hpp"
#include "struct_pack/derived_marco.hpp"
#include "struct_pack/error_code.hpp"
#include "struct_pack/md5_constexpr.hpp"
#include "struct_pack/packer.hpp"
#include "struct_pack/reflection.hpp"
#include "struct_pack/trivial_view.hpp"
#include "struct_pack/type_calculate.hpp"
#include "struct_pack/type_id.hpp"
#include "struct_pack/type_trait.hpp"
#include "struct_pack/unpacker.hpp"
#include "struct_pack/user_helper.hpp"
#include "struct_pack/varint.hpp"
#if __has_include(<expected>) && __cplusplus > 202002L
#include <expected>
#if __cpp_lib_expected >= 202202L
#else
#include "util/expected.hpp"
#endif
#else
#include "util/expected.hpp"
#endif
namespace struct_pack {
#if __cpp_lib_expected >= 202202L && __cplusplus > 202002L
template <class T, class E>
using expected = std::expected<T, E>;
template <class T>
using unexpected = std::unexpected<T>;
using unexpect_t = std::unexpect_t;
#else
template <class T, class E>
using expected = tl::expected<T, E>;
template <class T>
using unexpected = tl::unexpected<T>;
using unexpect_t = tl::unexpect_t;
#endif
inline std::error_code make_error_code(struct_pack::errc err) {
return std::error_code(static_cast<int>(err),
struct_pack::detail::category());
}
/*!
* \defgroup struct_pack struct_pack
*
* \brief yaLanTingLibs struct_pack
*
*
*
*/
/*!
* \ingroup struct_pack
* Get the error message corresponding to the error code `err`.
* @param err error code.
* @return error message.
*/
inline std::string_view error_message(struct_pack::errc err) noexcept {
return struct_pack::detail::make_error_message(err);
}
template <typename... Args>
constexpr std::uint32_t get_type_code() {
static_assert(sizeof...(Args) > 0);
std::uint32_t ret = 0;
if constexpr (sizeof...(Args) == 1) {
if constexpr (std::is_abstract_v<Args...>) {
struct_pack::detail::unreachable();
}
else {
ret = detail::get_types_code<Args...>();
}
}
else {
ret = detail::get_types_code<std::tuple<detail::remove_cvref_t<Args>...>>();
}
ret = ret - ret % 2;
return ret;
}
template <typename... Args>
constexpr decltype(auto) get_type_literal() {
static_assert(sizeof...(Args) > 0);
if constexpr (sizeof...(Args) == 1) {
using Types = decltype(detail::get_types<Args...>());
return detail::get_types_literal<Args..., Types>(
std::make_index_sequence<std::tuple_size_v<Types>>());
}
else {
return detail::get_types_literal<
std::tuple<detail::remove_cvref_t<Args>...>,
detail::remove_cvref_t<Args>...>();
}
}
/*!
* \ingroup struct_pack
* Get the byte size of the packing objects.
* TODO: add doc
* @tparam Args the types of packing objects.
* @param args the packing objects.
* @return byte size.
*/
template <uint64_t conf = sp_config::DEFAULT, typename... Args>
[[nodiscard]] constexpr struct_pack::serialize_buffer_size get_needed_size(
const Args &...args) {
return detail::get_serialize_runtime_info<conf>(args...);
}
template <uint64_t conf = sp_config::DEFAULT, typename Writer, typename... Args>
void serialize_to(Writer &writer, const Args &...args) {
static_assert(sizeof...(args) > 0);
if constexpr (struct_pack::writer_t<Writer>) {
auto info = detail::get_serialize_runtime_info<conf>(args...);
struct_pack::detail::serialize_to<conf>(writer, info, args...);
}
else if constexpr (detail::struct_pack_buffer<Writer>) {
static_assert(sizeof...(args) > 0);
auto data_offset = writer.size();
auto info = detail::get_serialize_runtime_info<conf>(args...);
auto total = data_offset + info.size();
detail::resize(writer, total);
auto real_writer =
struct_pack::detail::memory_writer{(char *)writer.data() + data_offset};
struct_pack::detail::serialize_to<conf>(real_writer, info, args...);
}
else {
static_assert(!sizeof(Writer),
"The Writer is not satisfied struct_pack::writer_t or "
"struct_pack_buffer requirement!");
}
}
template <uint64_t conf = sp_config::DEFAULT, typename... Args>
void serialize_to(char *buffer, serialize_buffer_size info,
const Args &...args) {
static_assert(sizeof...(args) > 0);
auto writer = struct_pack::detail::memory_writer{(char *)buffer};
struct_pack::detail::serialize_to<conf>(writer, info, args...);
}
template <uint64_t conf = sp_config::DEFAULT,
#if __cpp_concepts >= 201907L
detail::struct_pack_buffer Buffer,
#else
typename Buffer,
#endif
typename... Args>
void serialize_to_with_offset(Buffer &buffer, std::size_t offset,
const Args &...args) {
#if __cpp_concepts < 201907L
static_assert(detail::struct_pack_buffer<Buffer>,
"The buffer is not satisfied struct_pack_buffer requirement!");
#endif
static_assert(sizeof...(args) > 0);
auto info = detail::get_serialize_runtime_info<conf>(args...);
auto old_size = buffer.size();
detail::resize(buffer, old_size + offset + info.size());
auto writer = struct_pack::detail::memory_writer{(char *)buffer.data() +
old_size + offset};
struct_pack::detail::serialize_to<conf>(writer, info, args...);
}
template <
#if __cpp_concepts >= 201907L
detail::struct_pack_buffer Buffer = std::vector<char>,
#else
typename Buffer = std::vector<char>,
#endif
typename... Args>
[[nodiscard]] Buffer serialize(const Args &...args) {
#if __cpp_concepts < 201907L
static_assert(detail::struct_pack_buffer<Buffer>,
"The buffer is not satisfied struct_pack_buffer requirement!");
#endif
static_assert(sizeof...(args) > 0);
Buffer buffer;
serialize_to(buffer, args...);
return buffer;
}
template <
#if __cpp_concepts >= 201907L
detail::struct_pack_buffer Buffer = std::vector<char>,
#else
typename Buffer = std::vector<char>,
#endif
typename... Args>
[[nodiscard]] Buffer serialize_with_offset(std::size_t offset,
const Args &...args) {
#if __cpp_concepts < 201907L
static_assert(detail::struct_pack_buffer<Buffer>,
"The buffer is not satisfied struct_pack_buffer requirement!");
#endif
static_assert(sizeof...(args) > 0);
Buffer buffer;
serialize_to_with_offset(buffer, offset, args...);
return buffer;
}
template <uint64_t conf,
#if __cpp_concepts >= 201907L
detail::struct_pack_buffer Buffer = std::vector<char>,
#else
typename Buffer = std::vector<char>,
#endif
typename... Args>
[[nodiscard]] Buffer serialize(const Args &...args) {
#if __cpp_concepts < 201907L
static_assert(detail::struct_pack_buffer<Buffer>,
"The buffer is not satisfied struct_pack_buffer requirement!");
#endif
static_assert(sizeof...(args) > 0);
Buffer buffer;
serialize_to<conf>(buffer, args...);
return buffer;
}
template <uint64_t conf,
#if __cpp_concepts >= 201907L
detail::struct_pack_buffer Buffer = std::vector<char>,
#else
typename Buffer = std::vector<char>,
#endif
typename... Args>
[[nodiscard]] Buffer serialize_with_offset(std::size_t offset,
const Args &...args) {
#if __cpp_concepts < 201907L
static_assert(detail::struct_pack_buffer<Buffer>,
"The buffer is not satisfied struct_pack_buffer requirement!");
#endif
static_assert(sizeof...(args) > 0);
Buffer buffer;
serialize_to_with_offset<conf>(buffer, offset, args...);
return buffer;
}
#if __cpp_concepts >= 201907L
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
struct_pack::detail::deserialize_view View>
#else
template <
uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] struct_pack::err_code deserialize_to(T &t, const View &v,
Args &...args) {
detail::memory_reader reader{(const char *)v.data(),
(const char *)v.data() + v.size()};
detail::unpacker<detail::memory_reader, conf> in(reader);
return in.deserialize(t, args...);
}
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args>
[[nodiscard]] struct_pack::err_code deserialize_to(T &t, const char *data,
size_t size, Args &...args) {
detail::memory_reader reader{data, data + size};
detail::unpacker<detail::memory_reader, conf> in(reader);
return in.deserialize(t, args...);
}
#if __cpp_concepts >= 201907L
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
struct_pack::reader_t Reader>
#else
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
typename Reader,
typename = std::enable_if_t<struct_pack::reader_t<Reader>>>
#endif
[[nodiscard]] struct_pack::err_code deserialize_to(T &t, Reader &reader,
Args &...args) {
detail::unpacker<Reader, conf> in(reader);
std::size_t consume_len;
auto old_pos = reader.tellg();
auto ret = in.deserialize_with_len(consume_len, t, args...);
std::size_t delta = reader.tellg() - old_pos;
if SP_LIKELY (consume_len > 0) {
if SP_UNLIKELY (delta > consume_len) {
// TODO test this branch
ret = struct_pack::errc::invalid_buffer;
}
else {
reader.ignore(consume_len - delta);
}
}
return ret;
}
#if __cpp_concepts >= 201907L
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
struct_pack::detail::deserialize_view View>
#else
template <
uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] struct_pack::err_code deserialize_to(T &t, const View &v,
size_t &consume_len,
Args &...args) {
detail::memory_reader reader{(const char *)v.data(),
(const char *)v.data() + v.size()};
detail::unpacker<detail::memory_reader, conf> in(reader);
auto ret = in.deserialize_with_len(consume_len, t, args...);
if SP_LIKELY (!ret) {
consume_len = (std::max)((size_t)(reader.now - v.data()), consume_len);
}
else {
consume_len = 0;
}
return ret;
}
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args>
[[nodiscard]] struct_pack::err_code deserialize_to(T &t, const char *data,
size_t size,
size_t &consume_len,
Args &...args) {
detail::memory_reader reader{data, data + size};
detail::unpacker<detail::memory_reader, conf> in(reader);
auto ret = in.deserialize_with_len(consume_len, t, args...);
if SP_LIKELY (!ret) {
consume_len = (std::max)((size_t)(reader.now - data), consume_len);
}
else {
consume_len = 0;
}
return ret;
}
#if __cpp_concepts >= 201907L
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
struct_pack::detail::deserialize_view View>
#else
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args,
typename View>
#endif
[[nodiscard]] struct_pack::err_code deserialize_to_with_offset(T &t,
const View &v,
size_t &offset,
Args &...args) {
size_t sz;
auto ret =
deserialize_to(t, v.data() + offset, v.size() - offset, sz, args...);
offset += sz;
return ret;
}
template <uint64_t conf = sp_config::DEFAULT, typename T, typename... Args>
[[nodiscard]] struct_pack::err_code deserialize_to_with_offset(
T &t, const char *data, size_t size, size_t &offset, Args &...args) {
size_t sz;
auto ret = deserialize_to(t, data + offset, size - offset, sz, args...);
offset += sz;
return ret;
}
#if __cpp_concepts >= 201907L
template <typename... Args, struct_pack::detail::deserialize_view View>
#else
template <
typename... Args, typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] auto deserialize(const View &v) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to(ret.value(), v);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
template <typename... Args>
[[nodiscard]] auto deserialize(const char *data, size_t size) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
if (auto errc = deserialize_to(ret.value(), data, size); errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <typename... Args, struct_pack::reader_t Reader>
#else
template <typename... Args, typename Reader,
typename = std::enable_if_t<struct_pack::reader_t<Reader>>>
#endif
[[nodiscard]] auto deserialize(Reader &v) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to(ret.value(), v);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <typename... Args, struct_pack::detail::deserialize_view View>
#else
template <typename... Args, typename View>
#endif
[[nodiscard]] auto deserialize(const View &v, size_t &consume_len) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to(ret.value(), v, consume_len);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
template <typename... Args>
[[nodiscard]] auto deserialize(const char *data, size_t size,
size_t &consume_len) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to(ret.value(), data, size, consume_len);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <uint64_t conf, typename... Args,
struct_pack::detail::deserialize_view View>
#else
template <
uint64_t conf, typename... Args, typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] auto deserialize(const View &v) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to<conf>(ret.value(), v);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
template <uint64_t conf, typename... Args>
[[nodiscard]] auto deserialize(const char *data, size_t size) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
if (auto errc = deserialize_to<conf>(ret.value(), data, size); errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <uint64_t conf, typename... Args, struct_pack::reader_t Reader>
#else
template <uint64_t conf, typename... Args, typename Reader,
typename = std::enable_if_t<struct_pack::reader_t<Reader>>>
#endif
[[nodiscard]] auto deserialize(Reader &v) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to<conf>(ret.value(), v);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <uint64_t conf, typename... Args,
struct_pack::detail::deserialize_view View>
#else
template <uint64_t conf, typename... Args, typename View>
#endif
[[nodiscard]] auto deserialize(const View &v, size_t &consume_len) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to<conf>(ret.value(), v, consume_len);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
template <uint64_t conf, typename... Args>
[[nodiscard]] auto deserialize(const char *data, size_t size,
size_t &consume_len) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to<conf>(ret.value(), data, size, consume_len);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <typename... Args, struct_pack::detail::deserialize_view View>
#else
template <typename... Args, typename View>
#endif
[[nodiscard]] auto deserialize_with_offset(const View &v, size_t &offset) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to_with_offset(ret.value(), v, offset);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
template <typename... Args>
[[nodiscard]] auto deserialize_with_offset(const char *data, size_t size,
size_t &offset) {
expected<detail::get_args_type<Args...>, struct_pack::err_code> ret;
auto errc = deserialize_to_with_offset(ret.value(), data, size, offset);
if SP_UNLIKELY (errc) {
ret = unexpected<struct_pack::err_code>{errc};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
typename Field, struct_pack::detail::deserialize_view View>
#else
template <
typename T, size_t I, uint64_t conf = sp_config::DEFAULT, typename Field,
typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] struct_pack::err_code get_field_to(Field &dst, const View &v) {
using T_Field = std::tuple_element_t<I, decltype(detail::get_types<T>())>;
static_assert(std::is_same_v<Field, T_Field>,
"The dst's type is not correct. It should be as same as the "
"T's Ith field's type");
detail::memory_reader reader((const char *)v.data(),
(const char *)v.data() + v.size());
detail::unpacker<detail::memory_reader, conf> in(reader);
return in.template get_field<T, I>(dst);
}
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
typename Field>
[[nodiscard]] struct_pack::err_code get_field_to(Field &dst, const char *data,
size_t size) {
using T_Field = std::tuple_element_t<I, decltype(detail::get_types<T>())>;
static_assert(std::is_same_v<Field, T_Field>,
"The dst's type is not correct. It should be as same as the "
"T's Ith field's type");
detail::memory_reader reader{data, data + size};
detail::unpacker<detail::memory_reader, conf> in(reader);
return in.template get_field<T, I>(dst);
}
#if __cpp_concepts >= 201907L
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
typename Field, struct_pack::reader_t Reader>
#else
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
typename Field, typename Reader,
typename = std::enable_if_t<struct_pack::reader_t<Reader>>>
#endif
[[nodiscard]] struct_pack::err_code get_field_to(Field &dst, Reader &reader) {
using T_Field = std::tuple_element_t<I, decltype(detail::get_types<T>())>;
static_assert(std::is_same_v<Field, T_Field>,
"The dst's type is not correct. It should be as same as the "
"T's Ith field's type");
detail::unpacker<Reader, conf> in(reader);
return in.template get_field<T, I>(dst);
}
#if __cpp_concepts >= 201907L
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
struct_pack::detail::deserialize_view View>
#else
template <
typename T, size_t I, uint64_t conf = sp_config::DEFAULT, typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] auto get_field(const View &v) {
using T_Field = std::tuple_element_t<I, decltype(detail::get_types<T>())>;
expected<T_Field, struct_pack::err_code> ret;
auto ec = get_field_to<T, I, conf>(ret.value(), v);
if SP_UNLIKELY (ec) {
ret = unexpected<struct_pack::err_code>{ec};
}
return ret;
}
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT>
[[nodiscard]] auto get_field(const char *data, size_t size) {
using T_Field = std::tuple_element_t<I, decltype(detail::get_types<T>())>;
expected<T_Field, struct_pack::err_code> ret;
auto ec = get_field_to<T, I, conf>(ret.value(), data, size);
if SP_UNLIKELY (ec) {
ret = unexpected<struct_pack::err_code>{ec};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
struct_pack::reader_t Reader>
#else
template <typename T, size_t I, uint64_t conf = sp_config::DEFAULT,
typename Reader,
typename = std::enable_if_t<struct_pack::reader_t<Reader>>>
#endif
[[nodiscard]] auto get_field(Reader &reader) {
using T_Field = std::tuple_element_t<I, decltype(detail::get_types<T>())>;
expected<T_Field, struct_pack::err_code> ret;
auto ec = get_field_to<T, I, conf>(ret.value(), reader);
if SP_UNLIKELY (ec) {
ret = unexpected<struct_pack::err_code>{ec};
}
return ret;
}
#if __cpp_concepts >= 201907L
template <typename BaseClass, typename... DerivedClasses,
struct_pack::reader_t Reader>
#else
template <typename BaseClass, typename... DerivedClasses, typename Reader,
typename = std::enable_if_t<struct_pack::reader_t<Reader>>>
#endif
[[nodiscard]] struct_pack::expected<std::unique_ptr<BaseClass>,
struct_pack::err_code>
deserialize_derived_class(Reader &reader) {
static_assert(sizeof...(DerivedClasses) > 0,
"There must have a least one derived class");
static_assert(
struct_pack::detail::public_base_class_checker<
BaseClass, std::tuple<DerivedClasses...>>::value,
"the First type should be the base class of all derived class ");
constexpr auto has_hash_collision = struct_pack::detail::MD5_set<
std::tuple<DerivedClasses...>>::has_hash_collision;
if constexpr (has_hash_collision != 0) {
static_assert(!sizeof(std::tuple_element_t<has_hash_collision,
std::tuple<DerivedClasses...>>),
"ID collision happened, consider add member `static "
"constexpr uint64_t struct_pack_id` for collision type. ");
}
else {
struct_pack::expected<std::unique_ptr<BaseClass>, struct_pack::err_code>
ret;
auto ec = struct_pack::detail::deserialize_derived_class<BaseClass,
DerivedClasses...>(
ret.value(), reader);
if SP_UNLIKELY (ec) {
ret = unexpected<struct_pack::err_code>{ec};
}
return ret;
}
}
#if __cpp_concepts >= 201907L
template <typename BaseClass, typename... DerivedClasses,
struct_pack::detail::deserialize_view View>
#else
template <
typename BaseClass, typename... DerivedClasses, typename View,
typename = std::enable_if_t<struct_pack::detail::deserialize_view<View>>>
#endif
[[nodiscard]] struct_pack::expected<std::unique_ptr<BaseClass>,
struct_pack::err_code>
deserialize_derived_class(const View &v) {
detail::memory_reader reader{v.data(), v.data() + v.size()};
if constexpr (std::is_abstract_v<BaseClass>) {
return deserialize_derived_class<BaseClass, DerivedClasses...>(reader);
}
else {
return deserialize_derived_class<BaseClass, BaseClass, DerivedClasses...>(
reader);
}
}
template <typename BaseClass, typename... DerivedClasses>
[[nodiscard]] struct_pack::expected<std::unique_ptr<BaseClass>,
struct_pack::err_code>
deserialize_derived_class(const char *data, size_t size) {
detail::memory_reader reader{data, data + size};
if constexpr (std::is_abstract_v<BaseClass>) {
return deserialize_derived_class<BaseClass, DerivedClasses...>(reader);
}
else {
return deserialize_derived_class<BaseClass, BaseClass, DerivedClasses...>(
reader);
}
}
} // namespace struct_pack