Repo created

TMessagesProj/jni/voip/webrtc/base/strings/nullable_string16.h

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+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_STRINGS_NULLABLE_STRING16_H_
+#define BASE_STRINGS_NULLABLE_STRING16_H_
+
+#include <iosfwd>
+
+#include "base/base_export.h"
+#include "base/optional.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_util.h"
+
+namespace base {
+
+// This class is a simple wrapper for string16 which also contains a null
+// state.  This should be used only where the difference between null and
+// empty is meaningful.
+class BASE_EXPORT NullableString16 {
+ public:
+  NullableString16();
+  NullableString16(const NullableString16& other);
+  NullableString16(NullableString16&& other);
+  NullableString16(const string16& string, bool is_null);
+  explicit NullableString16(Optional<string16> optional_string16);
+  ~NullableString16();
+
+  NullableString16& operator=(const NullableString16& other);
+  NullableString16& operator=(NullableString16&& other);
+
+  const string16& string() const {
+    return string_ ? *string_ : EmptyString16();
+  }
+  bool is_null() const { return !string_; }
+  const Optional<string16>& as_optional_string16() const { return string_; }
+
+ private:
+  Optional<string16> string_;
+};
+
+inline bool operator==(const NullableString16& a, const NullableString16& b) {
+  return a.as_optional_string16() == b.as_optional_string16();
+}
+
+inline bool operator!=(const NullableString16& a, const NullableString16& b) {
+  return !(a == b);
+}
+
+BASE_EXPORT std::ostream& operator<<(std::ostream& out,
+                                     const NullableString16& value);
+
+}  // namespace base
+
+#endif  // BASE_STRINGS_NULLABLE_STRING16_H_