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QLinkedList size at declaration?

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  • K Offline
    K Offline
    kchandr7
    wrote on last edited by
    #1

    This might be a stupid question, but please don't shoot me down! I'm new to both C++ and Qt.

    Can size be specified at declaration in case of LinkedLists?

    @QLinkedList<int> list(10);@

    This throws me the following error:
    105: error: no matching function for call to 'QLinkedList<int>::QLinkedList(int)'

    But I've taken this line straight from the C++ GUI programming with Qt, SE.

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    • G Offline
      G Offline
      guziemic
      wrote on last edited by
      #2

      QLinkedList does not support predefinition of size. It growth when new element is linked to it. As I saw in "documentation":http://qt-project.org/doc/qt-4.8/QLinkedList.html there is no possibility to pre allocate size.
      But, if you need to reserve space for your list Qt offers "QList":http://qt-project.org/doc/qt-4.8/qlist.html and there is possibility to reserve space for elements "reserve":http://qt-project.org/doc/qt-4.8/qlist.html#reserve

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      • K Offline
        K Offline
        kchandr7
        wrote on last edited by
        #3

        Thanks, that makes sense. I guess the book is wrong then.

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        • U Offline
          U Offline
          utcenter
          wrote on last edited by
          #4

          It makes absolutely no sense for a linked list to pre-allocate elements because elements are not stored sequentially, not only is there nothing to gain from pre-allocation but it will mess up the implementation logic of the linked list.

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