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1 // Copyright (c) 2010 The Chromium Authors. All rights reserved. |
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2 // Use of this source code is governed by a BSD-style license that can be |
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3 // found in the LICENSE file. |
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4 |
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5 #ifndef BASE_STRINGS_NULLABLE_STRING16_H_ |
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6 #define BASE_STRINGS_NULLABLE_STRING16_H_ |
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7 |
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8 #include <iosfwd> |
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9 |
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10 #include "base/base_export.h" |
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11 #include "base/strings/string16.h" |
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12 |
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13 namespace base { |
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14 |
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15 // This class is a simple wrapper for string16 which also contains a null |
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16 // state. This should be used only where the difference between null and |
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17 // empty is meaningful. |
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18 class NullableString16 { |
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19 public: |
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20 NullableString16() : is_null_(true) { } |
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21 NullableString16(const string16& string, bool is_null) |
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22 : string_(string), is_null_(is_null) { |
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23 } |
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24 |
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25 const string16& string() const { return string_; } |
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26 bool is_null() const { return is_null_; } |
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27 |
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28 private: |
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29 string16 string_; |
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30 bool is_null_; |
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31 }; |
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32 |
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33 inline bool operator==(const NullableString16& a, const NullableString16& b) { |
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34 return a.is_null() == b.is_null() && a.string() == b.string(); |
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35 } |
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36 |
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37 inline bool operator!=(const NullableString16& a, const NullableString16& b) { |
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38 return !(a == b); |
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39 } |
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40 |
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41 BASE_EXPORT std::ostream& operator<<(std::ostream& out, |
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42 const NullableString16& value); |
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43 |
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44 } // namespace |
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45 |
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46 #endif // BASE_STRINGS_NULLABLE_STRING16_H_ |