added asio

include/asio/impl/error_code.ipp

@@ -0,0 +1,142 @@
+//
+// impl/error_code.ipp
+// ~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_IMPL_ERROR_CODE_IPP
+#define ASIO_IMPL_ERROR_CODE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+# include <winerror.h>
+#elif defined(ASIO_WINDOWS_RUNTIME)
+# include <windows.h>
+#else
+# include <cerrno>
+# include <cstring>
+# include <string>
+#endif
+#include "asio/detail/local_free_on_block_exit.hpp"
+#include "asio/detail/socket_types.hpp"
+#include "asio/error_code.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace error {
+namespace detail {
+
+ASIO_DECL std::error_condition error_number_to_condition(int ev);
+
+} // namespace detail
+} // namespace error
+namespace detail {
+
+class system_category : public error_category
+{
+public:
+  const char* name() const noexcept
+  {
+    return "asio.system";
+  }
+
+  std::string message(int value) const
+  {
+#if defined(ASIO_WINDOWS_RUNTIME) || defined(ASIO_WINDOWS_APP)
+    std::wstring wmsg(128, wchar_t());
+    for (;;)
+    {
+      DWORD wlength = ::FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM
+          | FORMAT_MESSAGE_IGNORE_INSERTS, 0, value,
+          MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+          &wmsg[0], static_cast<DWORD>(wmsg.size()), 0);
+      if (wlength == 0 && ::GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+      {
+        wmsg.resize(wmsg.size() + wmsg.size() / 2);
+        continue;
+      }
+      if (wlength && wmsg[wlength - 1] == '\n')
+        --wlength;
+      if (wlength && wmsg[wlength - 1] == '\r')
+        --wlength;
+      if (wlength)
+      {
+        std::string msg(wlength * 2, char());
+        int length = ::WideCharToMultiByte(CP_ACP, 0,
+            wmsg.c_str(), static_cast<int>(wlength),
+            &msg[0], static_cast<int>(wlength * 2), 0, 0);
+        if (length <= 0)
+          return "asio.system error";
+        msg.resize(static_cast<std::size_t>(length));
+        return msg;
+      }
+      else
+        return "asio.system error";
+    }
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+    char* msg = 0;
+    DWORD length = ::FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER
+        | FORMAT_MESSAGE_FROM_SYSTEM
+        | FORMAT_MESSAGE_IGNORE_INSERTS, 0, value,
+        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (char*)&msg, 0, 0);
+    detail::local_free_on_block_exit local_free_obj(msg);
+    if (length && msg[length - 1] == '\n')
+      msg[--length] = '\0';
+    if (length && msg[length - 1] == '\r')
+      msg[--length] = '\0';
+    if (length)
+      return msg;
+    else
+      return "asio.system error";
+#else // defined(ASIO_WINDOWS_DESKTOP) || defined(__CYGWIN__)
+#if !defined(__sun)
+    if (value == ECANCELED)
+      return "Operation aborted.";
+#endif // !defined(__sun)
+#if defined(__sun) || defined(__QNX__) || defined(__SYMBIAN32__)
+    using namespace std;
+    return strerror(value);
+#else
+    char buf[256] = "";
+    using namespace std;
+    return strerror_result(strerror_r(value, buf, sizeof(buf)), buf);
+#endif
+#endif // defined(ASIO_WINDOWS_DESKTOP) || defined(__CYGWIN__)
+  }
+
+  std::error_condition default_error_condition(int ev) const noexcept
+  {
+    return error::detail::error_number_to_condition(ev);
+  }
+
+private:
+  // Helper function to adapt the result from glibc's variant of strerror_r.
+  static const char* strerror_result(int, const char* s) { return s; }
+  static const char* strerror_result(const char* s, const char*) { return s; }
+};
+
+} // namespace detail
+
+const error_category& system_category()
+{
+  static detail::system_category instance;
+  return instance;
+}
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+// For implementation of asio::error::detail::error_number_to_condition.
+#include "asio/error.hpp"
+
+#endif // ASIO_IMPL_ERROR_CODE_IPP