How to inherit from boost :: asio :: streambuf after version 1.70.0? - c++

Question

After upgrade boost version 1.72.0, the following program which uses boost::asio cannot be compiled.I noticed that the read_until signature has changed since version 1.70.0.
Example in Coliru
#include <iostream>
#include <boost/asio.hpp>
class framed_streambuf: public boost::asio::streambuf
{
};
int main()
{
std::cout << "Using Boost "
<< BOOST_VERSION / 100000 << "." // major version
<< BOOST_VERSION / 100 % 1000 << "." // minor version
<< BOOST_VERSION % 100 // patch level
<< std::endl;
using boost::asio::ip::tcp;
framed_streambuf streambuf;
boost::asio::io_service io_service{1};
tcp::socket client_socket(io_service);
auto bytes_transferred = read_until(client_socket, streambuf, '#');
return 0;
}
Compilation errors:
/usr/local/include/boost/asio/impl/read_until.hpp: In instantiation of 'std::size_t boost::asio::read_until(SyncReadStream&, DynamicBuffer_v1&&, char, boost::system::error_code&, typename std::enable_if<(boost::asio::is_dynamic_buffer_v1<typename std::decay<_Func>::type>::value && (! boost::asio::is_dynamic_buffer_v2<typename std::decay<_Func>::type>::value))>::type*) [with SyncReadStream = boost::asio::basic_stream_socket<boost::asio::ip::tcp>; DynamicBuffer_v1 = framed_streambuf&; std::size_t = long unsigned int; typename std::enable_if<(boost::asio::is_dynamic_buffer_v1<typename std::decay<_Func>::type>::value && (! boost::asio::is_dynamic_buffer_v2<typename std::decay<_Func>::type>::value))>::type = void]':
/usr/local/include/boost/asio/impl/read_until.hpp:86:45: required from 'std::size_t boost::asio::read_until(SyncReadStream&, DynamicBuffer_v1&&, char, typename std::enable_if<(boost::asio::is_dynamic_buffer_v1<typename std::decay<_Func>::type>::value && (! boost::asio::is_dynamic_buffer_v2<typename std::decay<_Func>::type>::value))>::type*) [with SyncReadStream = boost::asio::basic_stream_socket<boost::asio::ip::tcp>; DynamicBuffer_v1 = framed_streambuf&; std::size_t = long unsigned int; typename std::enable_if<(boost::asio::is_dynamic_buffer_v1<typename std::decay<_Func>::type>::value && (! boost::asio::is_dynamic_buffer_v2<typename std::decay<_Func>::type>::value))>::type = void]'
main.cpp:20:70: required from here
/usr/local/include/boost/asio/impl/read_until.hpp:101:42: error: use of deleted function 'framed_streambuf::framed_streambuf(const framed_streambuf&)'
101 | typename decay<DynamicBuffer_v1>::type b(
| ^
main.cpp:4:7: note: 'framed_streambuf::framed_streambuf(const framed_streambuf&)' is implicitly deleted because the default definition would be ill-formed:
4 | class framed_streambuf: public boost::asio::streambuf
| ^~~~~~~~~~~~~~~~
main.cpp:4:7: error: use of deleted function 'boost::asio::basic_streambuf<>::basic_streambuf(const boost::asio::basic_streambuf<>&)'
In file included from /usr/local/include/boost/asio.hpp:36,
from main.cpp:2:
/usr/local/include/boost/asio/basic_streambuf.hpp:111:7: note: 'boost::asio::basic_streambuf<>::basic_streambuf(const boost::asio::basic_streambuf<>&)' is implicitly deleted because the default definition would be ill-formed:
111 | class basic_streambuf
| ^~~~~~~~~~~~~~~
/usr/local/include/boost/asio/basic_streambuf.hpp:111:7: error: 'boost::asio::detail::noncopyable::noncopyable(const boost::asio::detail::noncopyable&)' is private within this context
In file included from /usr/local/include/boost/asio/detail/std_fenced_block.hpp:23,
from /usr/local/include/boost/asio/detail/fenced_block.hpp:24,
from /usr/local/include/boost/asio/detail/executor_op.hpp:19,
from /usr/local/include/boost/asio/impl/system_executor.hpp:18,
from /usr/local/include/boost/asio/system_executor.hpp:129,
from /usr/local/include/boost/asio/associated_executor.hpp:21,
from /usr/local/include/boost/asio.hpp:21,
from main.cpp:2:
/usr/local/include/boost/asio/detail/noncopyable.hpp:32:3: note: declared private here
32 | noncopyable(const noncopyable&);
| ^~~~~~~~~~~
In file included from /usr/local/include/boost/asio/read_until.hpp:2795,
from /usr/local/include/boost/asio.hpp:114,
from main.cpp:2:
/usr/local/include/boost/asio/impl/read_until.hpp:108:59: error: 'framed_streambuf&' is not a class, struct, or union type
108 | typedef typename DynamicBuffer_v1::const_buffers_type buffers_type;
| ^~~~~~~~~~~~
/usr/local/include/boost/asio/impl/read_until.hpp:109:44: error: 'framed_streambuf&' is not a class, struct, or union type
109 | typedef buffers_iterator<buffers_type> iterator;
Since boost 1.70.0, the signature of read_until has changed：
template <typename SyncReadStream, typename DynamicBuffer_v1>
std::size_t read_until(SyncReadStream& s,
BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
char delim, boost::system::error_code& ec,
typename enable_if<
is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
&& !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type*)
I know very little about enable_if, does it matter here?