Initial Commit

include/asio/file_base.hpp

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+//
+// file_base.hpp
+// ~~~~~~~~~~~~~
+//
+// 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_FILE_BASE_HPP
+#define ASIO_FILE_BASE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_FILE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#if !defined(ASIO_WINDOWS)
+# include <fcntl.h>
+#endif // !defined(ASIO_WINDOWS)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// The file_base class is used as a base for the basic_stream_file and
+/// basic_random_access_file class templates so that we have a common place to
+/// define flags.
+class file_base
+{
+public:
+#if defined(GENERATING_DOCUMENTATION)
+  /// A bitmask type (C++ Std [lib.bitmask.types]).
+  typedef unspecified flags;
+
+  /// Open the file for reading.
+  static const flags read_only = implementation_defined;
+
+  /// Open the file for writing.
+  static const flags write_only = implementation_defined;
+
+  /// Open the file for reading and writing.
+  static const flags read_write = implementation_defined;
+
+  /// Open the file in append mode.
+  static const flags append = implementation_defined;
+
+  /// Create the file if it does not exist.
+  static const flags create = implementation_defined;
+
+  /// Ensure a new file is created. Must be combined with @c create.
+  static const flags exclusive = implementation_defined;
+
+  /// Open the file with any existing contents truncated.
+  static const flags truncate = implementation_defined;
+
+  /// Open the file so that write operations automatically synchronise the file
+  /// data and metadata to disk.
+  static const flags sync_all_on_write = implementation_defined;
+#else
+  enum flags
+  {
+#if defined(ASIO_WINDOWS)
+    read_only = 1,
+    write_only = 2,
+    read_write = 4,
+    append = 8,
+    create = 16,
+    exclusive = 32,
+    truncate = 64,
+    sync_all_on_write = 128
+#else // defined(ASIO_WINDOWS)
+    read_only = O_RDONLY,
+    write_only = O_WRONLY,
+    read_write = O_RDWR,
+    append = O_APPEND,
+    create = O_CREAT,
+    exclusive = O_EXCL,
+    truncate = O_TRUNC,
+    sync_all_on_write = O_SYNC
+#endif // defined(ASIO_WINDOWS)
+  };
+
+  // Implement bitmask operations as shown in C++ Std [lib.bitmask.types].
+
+  friend flags operator&(flags x, flags y)
+  {
+    return static_cast<flags>(
+        static_cast<unsigned int>(x) & static_cast<unsigned int>(y));
+  }
+
+  friend flags operator|(flags x, flags y)
+  {
+    return static_cast<flags>(
+        static_cast<unsigned int>(x) | static_cast<unsigned int>(y));
+  }
+
+  friend flags operator^(flags x, flags y)
+  {
+    return static_cast<flags>(
+        static_cast<unsigned int>(x) ^ static_cast<unsigned int>(y));
+  }
+
+  friend flags operator~(flags x)
+  {
+    return static_cast<flags>(~static_cast<unsigned int>(x));
+  }
+
+  friend flags& operator&=(flags& x, flags y)
+  {
+    x = x & y;
+    return x;
+  }
+
+  friend flags& operator|=(flags& x, flags y)
+  {
+    x = x | y;
+    return x;
+  }
+
+  friend flags& operator^=(flags& x, flags y)
+  {
+    x = x ^ y;
+    return x;
+  }
+#endif
+
+  /// Basis for seeking in a file.
+  enum seek_basis
+  {
+#if defined(GENERATING_DOCUMENTATION)
+    /// Seek to an absolute position.
+    seek_set = implementation_defined,
+
+    /// Seek to an offset relative to the current file position.
+    seek_cur = implementation_defined,
+
+    /// Seek to an offset relative to the end of the file.
+    seek_end = implementation_defined
+#else
+    seek_set = SEEK_SET,
+    seek_cur = SEEK_CUR,
+    seek_end = SEEK_END
+#endif
+  };
+
+protected:
+  /// Protected destructor to prevent deletion through this type.
+  ~file_base()
+  {
+  }
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_FILE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_FILE_BASE_HPP