working with binary values directly



  • Hello dears,
    These days i am going to work on qt and i am a new one in this major,i hope that help me.
    so, i would like to work by binary values directly in Qt, indeed i could find some info for visual but it does not work in Qt as you can see below:

    #define Ob(x) ((unsigned)Ob_(0 ## x ## uL))
    #define Ob_(x) ((x & 1) | (x >> 2 & 2) | (x >> 4 & 4) | (x >> 6 & 8) |
    (x >> 8 & 16) | (x >> 10 & 32) | (x >> 12 & 64) | (x >> 14 & 128)

    void setup_map(pattern_map& table)
    {
    table.insert(std::make_pair(Ob(0001101), 0));
    table.insert(std::make_pair(Ob(0011001), 1));
    table.insert(std::make_pair(Ob(0010011), 2));
    table.insert(std::make_pair(Ob(0111101), 3));
    table.insert(std::make_pair(Ob(0100011), 4));
    table.insert(std::make_pair(Ob(0110001), 5));
    table.insert(std::make_pair(Ob(0101111), 6));
    table.insert(std::make_pair(Ob(0111011), 7));
    table.insert(std::make_pair(Ob(0110111), 8));
    table.insert(std::make_pair(Ob(0001011), 9));
    }

    this table has problem,to be quiet honest i do not know really what should i go ??
    apologize for helping.
    Best,



  • You could use std::bitset if you really want to manipulate bits. But usually people use hexadecimal instead of binary...


  • Moderators

    If your compiler is C++14 compliant you can also use binary literals directly, e.g.

    table.insert(std::make_pair(0b00001101, 0));
    

    Btw. Qt is a library. It doesn't know or care about this stuff. There's no Qt code in your example whatsoever.



  • Hello
    thank you about that ,errors has been vanished ,but another problem has been occurred :
    OpenCV Error: Assertion failed (size.width>0 && size.height>0) in imshow, file /opt/opencv-3.1.0/modules/highgui/src/window.cpp, line 289
    terminate called after throwing an instance of 'cv::Exception'
    what(): /opt/opencv-3.1.0/modules/highgui/src/window.cpp:289: error: (-215) size.width>0 && size.height>0 in function imshow
    i could not find it in the net , really appreciated for helping.



  • I'm not an openCV expert, but the message is kind of self-explanatory: the picture you gave to the library has zero size.


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