Constant pointers

This is a discussion on Constant pointers within the C++ Programming forums, part of the General Programming Boards category; If I have this Code: const HermitCrab* t = &b; b.GetShellSize(); how can I make sure it compiles. Also if ...

  1. #1
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    Constant pointers

    If I have this

    Code:
    const HermitCrab* t = &b;
    b.GetShellSize();
    how can I make sure it compiles. Also if I have this

    Code:
                  HermitCrab a(1);
                  const HermitCrab b(3);
    Will Compile    Code…
      (Yes/No)?
    ____________  1  HermitCrab* const q = &a;
                    q->MoveIntoShell(8);
    ____________  2  const HermitCrab* p = &a;
                    p->MoveIntoShell(8);
    ____________ 3   HermitCrab* const m = &b;
                    m->MoveIntoShell(2);
    ____________ 4   const HermitCrab* r = &b;
                    r->MoveIntoShell(8);
    ____________  5  const HermitCrab* p = &b;
                    p = &a;
    are these answers right
    1) No because the pointer is read only
    2) Yes
    3) No because the object is constant therefore it most have a const object pointer
    4) Yes
    5) Yes

  2. #2
    Code Goddess Prelude's Avatar
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    >how can I make sure it compiles.
    Hmm, define HermitCrab with a GetShellSize member function and define b to be an object of type HermitCrab.

    >1) No because the pointer is read only
    And what does that have to do with calling a member function on the pointed to object?

    >2) Yes
    Why?

    >4) Yes
    Why?

    >5) Yes
    Why?
    My best code is written with the delete key.

  3. #3
    and the hat of wrongness Salem's Avatar
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    Erm, it takes what - 30 seconds to actually type that into a small program and see if you get any 'you can't do that it's const' type error messages.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
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