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      1 /*
      2  * Copyright (C) 2012 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef BitArray_h
     27 #define BitArray_h
     28 
     29 #include <string.h>
     30 #include "wtf/Assertions.h"
     31 
     32 namespace WTF {
     33 
     34 template<unsigned arraySize>
     35 class BitArray {
     36 public:
     37     BitArray()
     38     {
     39         memset(m_data, 0, sizeof(m_data));
     40     }
     41 
     42     void set(unsigned index)
     43     {
     44         ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
     45         m_data[index / 8] |= 1 << (index & 7);
     46     }
     47 
     48     bool get(unsigned index) const
     49     {
     50         ASSERT_WITH_SECURITY_IMPLICATION(index < arraySize);
     51         return !!(m_data[index / 8] & (1 << (index & 7)));
     52     }
     53 
     54 private:
     55     unsigned char m_data[arraySize / 8 + 1];
     56 };
     57 
     58 } // namespace WTF
     59 
     60 using WTF::BitArray;
     61 
     62 #endif // BitArray_h
     63