Method ImBitArray

src/third-party/imgui/imgui_internal.h:547–547

{
    ImU32           Storage[(BITCOUNT + 31) >> 5];
    ImBitArray()                                { ClearAllBits(); }
    void            ClearAllBits()              { memset(Storage, 0, sizeof(Storage)); }
    void            SetAllBits()                { memset(Storage, 255, sizeof(Storage)); }
    bool            TestBit(int n) const        { IM_ASSERT(n + OFFSET < BITCOUNT); return ImBitArrayTestBit(Storage, n + OFFSET); }