Switching elements in a list

This is a discussion on Switching elements in a list within the C++ Programming forums, part of the General Programming Boards category; Hey, Is it possible to swap elements in a list? For example, if my list looked like Code: list<int> myList ...

  1. #1
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    Switching elements in a list

    Hey,

    Is it possible to swap elements in a list? For example, if my list looked like

    Code:
    list<int> myList = {1, 2, 3, 4} (incorrect syntax, i know)
    Is there some way to switch the 3 and 4 around, how it would then look like {1, 2, 4, 3} ?
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  2. #2
    and the hat of sweating
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    Did you try the std::swap() function in <algorithm>?
    I think you should be able to just swap the iterators to 2 elements.

  3. #3
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    But how would you randomly access elements in list? And since you can't randomly access list elements, you'd have to swap iterators, or iter_swap, which you'd have increment/decrement through a tedious process to get where you intend it to be.

  4. #4
    Algorithm Dissector iMalc's Avatar
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    What are you wanting to swap item positions for... Are you implementing a sorting algorithm?

    Are the ones you want to swap always next to each other?

    btw You aren't forced to be bound by the notion of swapping when it comes to lists, and indeed it can be better to not attempt to do such things. For example you can achieve the reordering you want by removing 4, and reinserting it between 2 and 3.
    Whatever you do, don't treat a list as though it provides random access.
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