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1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ |
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2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ |
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3 /* This Source Code Form is subject to the terms of the Mozilla Public |
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4 * License, v. 2.0. If a copy of the MPL was not distributed with this |
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5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
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6 |
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7 #ifndef mozilla_Range_h |
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8 #define mozilla_Range_h |
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9 |
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10 #include "mozilla/NullPtr.h" |
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11 #include "mozilla/RangedPtr.h" |
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12 |
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13 #include <stddef.h> |
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14 |
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15 namespace mozilla { |
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16 |
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17 // Range<T> is a tuple containing a pointer and a length. |
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18 template <typename T> |
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19 class Range |
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20 { |
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21 RangedPtr<T> mStart; |
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22 RangedPtr<T> mEnd; |
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23 |
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24 typedef void (Range::* ConvertibleToBool)(); |
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25 void nonNull() {} |
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26 |
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27 public: |
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28 Range() : mStart(nullptr, 0), mEnd(nullptr, 0) {} |
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29 Range(T* p, size_t len) |
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30 : mStart(p, p, p + len), |
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31 mEnd(p + len, p, p + len) |
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32 {} |
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33 |
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34 RangedPtr<T> start() const { return mStart; } |
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35 RangedPtr<T> end() const { return mEnd; } |
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36 size_t length() const { return mEnd - mStart; } |
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37 |
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38 T& operator[](size_t offset) { |
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39 return mStart[offset]; |
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40 } |
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41 |
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42 const T& operator[](size_t offset) const { |
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43 return mStart[offset]; |
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44 } |
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45 |
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46 operator ConvertibleToBool() const { return mStart ? &Range::nonNull : 0; } |
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47 }; |
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48 |
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49 } // namespace mozilla |
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50 |
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51 #endif /* mozilla_Range_h */ |