Thread: object and constructor

  1. #1
    Registered User
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    May 2006
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    object and constructor

    Hello

    How can I solve the next problem:

    Code:
    class A {
    public:
    A() : m_b(m_c) { }
    B m_b;
    C m_c;
    };
    
    class B {
    public:
    B(C &ref) : m_c(ref) { }
    C &m_c;
    };
    The problem is I want to pass a reference of object (class C) which wasnt 'built' yet to class B.
    What can I do about this?

  2. #2
    Registered User
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    Place the declaration of m_b after m_c inside class A. Then m_c will be constructed first, and can be passed to m_b. Another option is to just use a (smart) pointer that can be assigned after construction.

    This design can be confusing and cause maintenance headaches, though, so be sure you need to do that.

  3. #3
    Registered User
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    Program still crashes. Could it be because I pass *this along with the C's reference?

  4. #4
    Algorithm Dissector iMalc's Avatar
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    Quote Originally Posted by l2u View Post
    Program still crashes. Could it be because I pass *this along with the C's reference?
    You'll have to post the real code.
    My homepage
    Advice: Take only as directed - If symptoms persist, please see your debugger

    Linus Torvalds: "But it clearly is the only right way. The fact that everybody else does it some other way only means that they are wrong"

  5. #5
    Cat without Hat CornedBee's Avatar
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    There's nothing wrong with passing and storing a reference to an uninitialized object. You just can't use it until it has been initialized.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
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