Returning the address of a member structure

This is a discussion on Returning the address of a member structure within the C++ Programming forums, part of the General Programming Boards category; Is it possible to retrieve the address of a member structure? I tried the following code but it doesn't work: ...

  1. #1
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    Returning the address of a member structure

    Is it possible to retrieve the address of a member structure?

    I tried the following code but it doesn't work:

    Code:
    class SomeClass
    {
    private:
    struct x
    {int a
    } y;
    public:
    int struct_address(){return &y;}
    }
    
    ...
    
    cout << classinstance.struct_address() << endl;
    How would you access the address of a member variable or structure or whatever?

  2. #2
    carry on JaWiB's Avatar
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    First of all, fix your indentation.

    Second, why do you even want to do this? I can't think of a good reason.
    "Think not but that I know these things; or think
    I know them not: not therefore am I short
    Of knowing what I ought."
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  3. #3
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    Nevermind, got it to work.

    Code:
    	...
    	int* struct_address(){return (int*) &y;}
    FYI, I need to know how bitfield variables are configured in the memory so that I can perform a bitfield operation on them later.

  4. #4
    semi-colon generator ChaosEngine's Avatar
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    Quote Originally Posted by cunnus88
    Nevermind, got it to work.

    Code:
    	...
    	int* struct_address(){return (int*) &y;}
    FYI, I need to know how bitfield variables are configured in the memory so that I can perform a bitfield operation on them later.
    that's an ugly hack. if you need to return the address of your struct, don't cast away your type info.
    Code:
    class SomeClass
    {
    private:
       struct x
       {
           int a
        } y;
    public:
       // return type matches type being returned
       x* struct_address(){return &y;}
    };
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  5. #5
    and the hat of wrongness Salem's Avatar
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    That kind of interface is very bad.
    You should never allow direct access to the internal data of your class.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
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