Return 2 variables?

This is a discussion on Return 2 variables? within the C++ Programming forums, part of the General Programming Boards category; Is it possible to return 2 variables for ex. Code: int hello(int x, int y) { x++; y++; return x,y; ...

  1. #1
    Hi ay_okay's Avatar
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    Return 2 variables?

    Is it possible to return 2 variables for ex.
    Code:
    int hello(int x, int y)
    {
       x++;
       y++;
       return x,y;
    }

  2. #2
    Banned master5001's Avatar
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    Example:
    Code:
    void hello(int &x, int &y) {
      x++;
      y++;
    }

  3. #3
    & the hat of GPL slaying Thantos's Avatar
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    No. But you can wrap them up in a struct and then return the struct.

    Code:
    struct Return2Ints {
      int x;
      int y;
    };
    
    Return2Ints hello (int x, int y)
    {
      return Return2Ints(x+1,y+1);
    }

  4. #4
    Hi ay_okay's Avatar
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    how would i recieve it?
    Code:
    x = return2numbers();
    xbeing a struct?

  5. #5
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    From Thantos' example:
    Code:
    Return2Ints someStruct = hello (1,2);

  6. #6
    & the hat of GPL slaying Thantos's Avatar
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    Adding to bithub:
    To get to the actual values
    Code:
    int a = someStruct.x;
    int b = someStruct.y;

  7. #7
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    A generic way to do this is to return an std::pair:

    std::pair<int,int> hello(int x, int y); { return std::make_pair (x,y); }

    std::pair bla = hello(1,2);
    cout << bla.first; //x

    Tuples (look up Boost.Tuple) let you return any number of values. You can use Boost.Tuple in a similar way to std::pair.

  8. #8
    Registered User Codeplug's Avatar
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    >> return Return2Ints(x+1,y+1);
    Return2Ints needs a proper constructor for that to work.
    Code:
    struct Return2Ints {
      int x;
      int y;
    
      Return2Ints(int x_, int y_) : x(x_), y(y_) {}
    };
    gg

  9. #9
    & the hat of GPL slaying Thantos's Avatar
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    Opps forgot about that. Though it can be done without a constructor:
    Code:
    Return2Ints hello(int x, int y)
    {
      Return2Ints ret = {x+1,y+1};
      return ret;
    }

  10. #10
    Registered User hk_mp5kpdw's Avatar
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    Quote Originally Posted by azteched
    A generic way to do this is to return an std::pair:

    std::pair<int,int> hello(int x, int y); { return std::make_pair (x,y); }

    std::pair<int,int> bla = hello(1,2);
    cout << bla.first; //x

    Tuples (look up Boost.Tuple) let you return any number of values. You can use Boost.Tuple in a similar way to std::pair.
    Added part in red above.
    "Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
    -Christopher Hitchens

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