ptrandflags.h

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (c) 2009, Google Inc. All rights reserved.
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#ifndef PtrAndFlags_h
#define PtrAndFlags_h

#include <wtf/Assertions.h>

namespace WTF {
    template<class T, typename FlagEnum> class PtrAndFlags {
    public:
        PtrAndFlags() : m_ptrAndFlags(0) {}

        bool isFlagSet(FlagEnum flagNumber) const { ASSERT(flagNumber < 2); return m_ptrAndFlags & (1 << flagNumber); }
        void setFlag(FlagEnum flagNumber) { ASSERT(flagNumber < 2); m_ptrAndFlags |= (1 << flagNumber);}
        void clearFlag(FlagEnum flagNumber) { ASSERT(flagNumber < 2); m_ptrAndFlags &= ~(1 << flagNumber);}
        T* get() const { return reinterpret_cast<T*>(m_ptrAndFlags & ~3); }
        void set(T* ptr) { ASSERT(!(reinterpret_cast<intptr_t>(ptr) & 3)); m_ptrAndFlags = reinterpret_cast<intptr_t>(ptr) | (m_ptrAndFlags & 3);}
    private:
        intptr_t m_ptrAndFlags;
    };
} // namespace WTF

using WTF::PtrAndFlags;

#endif // PtrAndFlags_h