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    <ol> <li><p>Think of the requirements of the addresses of items in a linked-list (<code>list</code>). They don't need to be sequential in memory.</p></li> <li><p><code>delete</code> is something that's manually done on pointers, it wouldn't happen automatically (even if the pointer goes out of scope) (unless done in some API). Iterators are (generally) classes, so <code>delete</code> would not even apply. The iterator would get destructed though.</p> <p>You can also probably classify a pointer as an iterator. But <code>delete</code> will still not be called automatically.</p></li> <li><p>Note that <a href="http://www.cplusplus.com/reference/iterator/" rel="nofollow">this only applies to random access iterators</a>. You can calculate the number of items in a container as follows:</p> <pre><code>int count = 0; for (iterator it = begin(); it != end(); ++it, ++count) { } </code></pre> <p>so you increment <code>begin()</code> <code>count</code> times to get to <code>end()</code>,<br> so <code>begin() + count = end()</code>,<br> so <code>end() - begin() = count</code>, and <code>count = size()</code>,<br> so <code>end() - begin() = size()</code></p></li> <li><p>This is not the way C++ works. Although there are design patterns to achieve this behaviour, usually when modifying a class, it's your responsibility to ensure any dependent classes are updated if invalidated. When you'd try to use an iterator of a container that went out of scope, this would result in undefined behaviour.</p></li> <li><p><code>end()</code> is past the last element, probably with something like this in mind: (I'm sure among other reasons)</p> <pre><code>for (iterator it = begin(); it != end(); ++it) </code></pre></li> </ol>
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    1. POContainers and iterators (multiple choice)
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    1. COFor #3, "when the expression myC.end()-myC.begin() is well-defined" would imply that they're random access iterators. So it is indeed true.
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      1. USMark Ransom
    2. COBy your own list, if the expression `myC.end()-myC.begin()` is *well-defined* as the question states it is, then it must be (and can only be) a RandomAccessIterator, at which point #3 is **true**, not false.
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    3. COMisread that one, edited.
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