mysql/detail/any_resumable_ref.hpp

0001 //
0002 // Copyright (c) 2019-2024 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007
0008 #ifndef BOOST_MYSQL_DETAIL_ANY_RESUMABLE_REF_HPP
0009 #define BOOST_MYSQL_DETAIL_ANY_RESUMABLE_REF_HPP
0010
0011 #include <boost/mysql/detail/next_action.hpp>
0012
0013 #include <cstddef>
0014 #include <type_traits>
0015
0016 namespace boost {
0017 namespace mysql {
0018 namespace detail {
0019
0020 class any_resumable_ref
0021 {
0022     template <class T>
0023     static next_action do_resume(void* self, error_code ec, std::size_t bytes_transferred)
0024     {
0025         return static_cast<T*>(self)->resume(ec, bytes_transferred);
0026     }
0027
0028     using fn_t = next_action (*)(void*, error_code, std::size_t);
0029
0030     void* algo_{};
0031     fn_t fn_{};
0032
0033 public:
0034     template <class T, class = typename std::enable_if<!std::is_same<T, any_resumable_ref>::value>::type>
0035     explicit any_resumable_ref(T& op) noexcept : algo_(&op), fn_(&do_resume<T>)
0036     {
0037     }
0038
0039     next_action resume(error_code ec, std::size_t bytes_transferred)
0040     {
0041         return fn_(algo_, ec, bytes_transferred);
0042     }
0043 };
0044
0045 }  // namespace detail
0046 }  // namespace mysql
0047 }  // namespace boost
0048
0049 #endif