1 files changed, 56 insertions, 0 deletions
diff --git a/include/cru/base/io/OpenFileFlag.h b/include/cru/base/io/OpenFileFlag.h
new file mode 100644
index 00000000..4a5789fb
--- /dev/null
+++ b/include/cru/base/io/OpenFileFlag.h
@@ -0,0 +1,56 @@
+#pragma once
+
+#include "../Bitmask.h"
+
+namespace cru::io {
+namespace details {
+struct OpenFileFlagTag {};
+}  // namespace details
+using OpenFileFlag = Bitmask<details::OpenFileFlagTag>;
+
+struct OpenFileFlags {
+  /**
+   * \brief for reading
+   * If the file does not exist, FileNotExistException should be thrown.
+   */
+  static constexpr OpenFileFlag Read{0x1};
+
+  /**
+   * \brief for writing
+   * If the file does not exist and Create is not specified,
+   * FileNotExistException should be thrown.
+   */
+  static constexpr OpenFileFlag Write{0x2};
+
+  /**
+   * \brief when writing, seek to end first
+   * Only effective for writing.
+   */
+  static constexpr OpenFileFlag Append{0x4};
+
+  /**
+   * \brief when writing, truncate the file to empty
+   * Only effective for writing.
+   * So the content is erased! Be careful!
+   */
+  static constexpr OpenFileFlag Truncate{0x8};
+
+  /**
+   * \brief when writing, if the file does not exist, create one
+   * Only effective for writing. When file does not exist, FileNotExistException
+   * will NOT be thrown and a new file will be created.
+   */
+  static constexpr OpenFileFlag Create{0x10};
+
+  /**
+   *  TODO: ???
+   */
+  static constexpr OpenFileFlag Exclusive{0x20};
+};
+
+/**
+ * Append, Truncate, Create must be used with Write.
+ * Append and Truncate must not be used together.
+ */
+bool CheckOpenFileFlag(OpenFileFlag flags);
+}  // namespace cru::io