net.h

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// Networking implementation details -*- C++ -*-
 
// Copyright (C) 2015-2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
 
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
 
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.
 
/** @file experimental/bits/net.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{experimental/net}
 */
 
#ifndef _GLIBCXX_EXPERIMENTAL_NET_H
#define _GLIBCXX_EXPERIMENTAL_NET_H 1
 
#pragma GCC system_header
 
#if __cplusplus >= 201402L
 
#include <type_traits>
#include <system_error>
#include <experimental/netfwd>
 
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace experimental
{
namespace net
{
inline namespace v1
{
 
  /** @addtogroup networking-ts
   *  @{
   */
 
  template<typename _CompletionToken, typename _Signature, typename>
    class async_result;
 
  /// @cond undocumented
 
  // A type denoted by DEDUCED in the TS.
  template<typename _CompletionToken, typename _Signature>
    using __deduced_t = typename
      async_result<decay_t<_CompletionToken>, _Signature, void>::return_type;
 
  // Trait to check for construction from const/non-const lvalue/rvalue.
  template<typename _Tp>
    using __is_value_constructible = typename __and_<
      is_copy_constructible<_Tp>, is_move_constructible<_Tp>,
      is_constructible<_Tp, _Tp&>, is_constructible<_Tp, const _Tp&&>
      >::type;
 
  struct __throw_on_error
  {
    explicit
    __throw_on_error(const char* __msg) : _M_msg(__msg) { }
 
    ~__throw_on_error() noexcept(false)
    {
      if (_M_ec)
        _GLIBCXX_THROW_OR_ABORT(system_error(_M_ec, _M_msg));
    }
 
    __throw_on_error(const __throw_on_error&) = delete;
    __throw_on_error& operator=(const __throw_on_error&) = delete;
 
    operator error_code&() noexcept { return _M_ec; }
 
    const char* _M_msg;
    error_code _M_ec;
  };
 
  /// @endcond
 
  // Base class for types meeting IntegerSocketOption requirements.
  template<typename _Tp>
    struct __sockopt_base
    {
      __sockopt_base() = default;
 
      explicit __sockopt_base(int __val) : _M_value(__val) { }
 
      int value() const noexcept { return _M_value; }
 
      template<typename _Protocol>
        void*
        data(const _Protocol&) noexcept
        { return std::addressof(_M_value); }
 
      template<typename _Protocol>
        const void*
        data(const _Protocol&) const noexcept
        { return std::addressof(_M_value); }
 
      template<typename _Protocol>
        size_t
        size(const _Protocol&) const noexcept
        { return sizeof(_M_value); }
 
      template<typename _Protocol>
        void
        resize(const _Protocol&, size_t __s)
        {
          if (__s != sizeof(_M_value))
            __throw_length_error("invalid value for socket option resize");
        }
 
    protected:
      _Tp _M_value { };
    };
 
  // Base class for types meeting BooleanSocketOption requirements.
  template<>
    struct __sockopt_base<bool> : __sockopt_base<int>
    {
      __sockopt_base() = default;
 
      explicit __sockopt_base(bool __val) : __sockopt_base<int>(__val) { }
 
      bool value() const noexcept { return __sockopt_base<int>::_M_value; }
      explicit operator bool() const noexcept { return value(); }
      bool operator!() const noexcept { return !value(); }
    };
 
  template<typename _Derived, typename _Tp = int>
    struct __sockopt_crtp : __sockopt_base<_Tp>
    {
      using __sockopt_base<_Tp>::__sockopt_base;
 
      _Derived&
      operator=(_Tp __value)
      {
        __sockopt_base<_Tp>::_M_value = __value;
        return static_cast<_Derived&>(*this);
      }
 
      template<typename _Protocol>
        int
        level(const _Protocol&) const noexcept
        { return _Derived::_S_level; }
 
      template<typename _Protocol>
        int
        name(const _Protocol&) const noexcept
        { return _Derived::_S_name; }
    };
 
  /// @}
 
} // namespace v1
} // namespace net
} // namespace experimental
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
 
#endif // C++14
 
#endif // _GLIBCXX_EXPERIMENTAL_NET_H