如何使用boost :: dynamic_bitset成员序列化一个类？
#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <boost/dynamic_bitset.hpp>
#include <boost/serialization/bitset.hpp>
#include <sstream>
class A
{
friend class boost::serialization::access;
boost::dynamic_bitset<> x;
template<class Archive>
void serialize(Archive & ar, const unsigned int){
ar & x;
}
};
int main()
{
A a;
std::stringstream ss;
boost::archive::text_oarchive oa(ss);
oa << a;
return 0;
}
编译会产生错误（提升1.57）
In file included from /usr/include/boost/serialization/extended_type_info_typeid.hpp:37:0,
from /usr/include/boost/archive/detail/oserializer.hpp:38,
from /usr/include/boost/archive/detail/interface_oarchive.hpp:23,
from /usr/include/boost/archive/detail/common_oarchive.hpp:22,
from /usr/include/boost/archive/basic_text_oarchive.hpp:32,
from /usr/include/boost/archive/text_oarchive.hpp:31,
from dynamic_bitset_setial.cpp:1:
/usr/include/boost/serialization/access.hpp: In static member function ‘static void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive, T = boost::dynamic_bitset<>]’:
/usr/include/boost/serialization/serialization.hpp:69:5: instantiated from ‘void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive, T = boost::dynamic_bitset<>]’
/usr/include/boost/serialization/serialization.hpp:128:9: instantiated from ‘void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive, T = boost::dynamic_bitset<>]’
/usr/include/boost/archive/detail/oserializer.hpp:148:5: instantiated from ‘void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::text_oarchive, T = boost::dynamic_bitset<>]’
dynamic_bitset_setial.cpp:25:1: instantiated from here
/usr/include/boost/serialization/access.hpp:118:9: error: ‘class boost::dynamic_bitset<>’ has no member named ‘serialize’
答案 0 :(得分：5)
我继续 filed the pull request 为Boost Dynamic Bitset添加序列化支持
使用公共界面进行序列化并非最佳，因为
to_block_range()/from_block_range()需要复制m_bits（以及后续resize()）。我在Boost Dynamic Bitset中添加了一个通用实现。这些更改与开发或主控（1_58_0）完全合并。
更改
实施添加了
- 最小的侵入性，只有一个嵌套的朋友（
访问所需的朋友class serialization_impl;）已向前宣布为＆＃34; key-hole＆＃34;通过- 此类以及Boost Serialization的实际ADL挂钩在单独的头文件（
dynamic_bitset/serialization.hpp中实现，类似于其他具有序列化支持的boost库）。- 这意味着除非实际包含
boost/dynamic_bitset/serialization.hpp，否则存在对Boost序列化内容的零依赖性- 实现零拷贝（利用Boost序列化中
std::vector<Block>的内置支持）测试
pull请求中的第二次提交会添加此功能的测试。我不确定如何将
dyn_bitset_unit_tests5.cpp添加到Jamfile中。我想必须采取其他措施来确保链接到Boost System和Boost Serialization。我使用一个简单的包装器自己运行测试：#include <modular-boost/libs/dynamic_bitset/dyn_bitset_unit_tests5.cpp> int main() { test_main(0, nullptr); }然后可以编译并运行，例如
g++ main.cpp -lboost_system -lboost_serialization && ./a.out没有输出意味着没有错误。
答案 1 :(得分：4)
dynamic_bitset<>不可序列化，因为您已经发现（std::bitset<N>是不同的类型）。
不过不用担心，你可以毫不费力地添加它：
namespace boost { namespace serialization {
template <typename Ar, typename Block, typename Alloc>
void save(Ar& ar, dynamic_bitset<Block, Alloc> const& bs, unsigned) {
size_t num_bits = bs.size();
std::vector<Block> blocks(bs.num_blocks());
to_block_range(bs, blocks.begin());
ar & num_bits & blocks;
}
template <typename Ar, typename Block, typename Alloc>
void load(Ar& ar, dynamic_bitset<Block, Alloc>& bs, unsigned) {
size_t num_bits;
std::vector<Block> blocks;
ar & num_bits & blocks;
bs.resize(num_bits);
from_block_range(blocks.begin(), blocks.end(), bs);
bs.resize(num_bits);
}
template <typename Ar, typename Block, typename Alloc>
void serialize(Ar& ar, dynamic_bitset<Block, Alloc>& bs, unsigned version) {
split_free(ar, bs, version);
}
} }
这有效，例如的 Live On Coliru
int main() {
A a;
for (int i=0; i<128; ++i)
a.x.resize(11*i, i%2);
std::stringstream ss;
{
boost::archive::text_oarchive oa(ss);
oa << a;
}
std::cout << ss.str();
{
boost::archive::text_iarchive ia(ss);
A b;
ia >> b;
assert(a.x == b.x);
}
}
请注意，如果您无法复制块矢量，那么直接在m_bits级别添加序列化同样容易，但这需要进行干扰性更改（需要访问朋友权限）最小值）。
这样的事情很容易被添加到拉取请求中。