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    <p>You write (emphasis by me): </p> <blockquote> <p>§23.1.2.8 in the standard states that insertion/deletion operations on a set/map will not invalidate any iterators <em>to those objects</em> (except iterators pointing to a deleted element).</p> </blockquote> <p>Actually, the text of 23.1.2/8 is a bit different (again, emphasis by me): </p> <blockquote> <p>The insert members shall not affect the validity of iterators and references <em>to the container</em>, and the erase members shall invalidate only iterators and references to the erased elements.</p> </blockquote> <p>I read this as: If you have a map, and somehow obtain an iterator into this map (again: it doesn't say <em>to an object</em> in the map), this iterator will stay valid despite insertion and removal of elements. Assuming <code>std::map&lt;K,V&gt;::end()</code> obtains an "iterator into the map", it should not be invalidated by insertion/removal. </p> <p>This, of course, leaves the question whether "not invalidated" means it will always have the same value. My personal assumption is that this is not specified. However, in order for the "not invalidated" phrase to make sense, all results of <code>std::map&lt;K,V&gt;::end()</code> for the same map must always compare equal even in the face of insertions/removal: </p> <pre><code>my_map_t::iterator old_end = my_map.end(); // wildly change my_map assert( old_end == my_map.end() ); </code></pre> <p>My interpretation is that, if <code>old_end</code> remains "valid" throughout changes to the map (as the standard promisses), then that assertion should pass. </p> <p><em>Disclaimer</em>: I am not a native speaker and have a <em>very</em> hard time digesting that dreaded legaleze of the Holy PDF. In fact, in general I avoid it like the plague. </p> <p>Oh, and my first thought also was: The question is interesting from an academic POV, but why doesn't he simply store keys instead of iterators? </p>
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    1. POIs end() required to be constant in an STL map/set?
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    1. COYes, the essence of the question is whether that interpretation is correct.
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    2. CO"The insert members shall not affect the validity of (iterators) and (references to the container)". I think this is the proper parentheses arrangement--at least it makes sense, while your interpretation does not: there's not such a ting as "iterator to the container". However, there exist "iterators *over* containers".
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    3. CO@Pavel: If "there's no such thing as iterators _to the container"_, why would there be references _to the container_? I'm not convinced, although I agree that the phrase is far from being clear.
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