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  • $\begingroup$ Of course a compiler could optimize this away - this was very common on x86, for example, because of its powerful memory addressing; especially since 486 and Pentium. And of course, just have a look at any modern disassembled code - in most cases, you will not find any direct indexing from the base of the array anyway. Ultimately, in many cases, indexing an array is a relic anyway - for most cases where you see indexing, what you really want is iteration. It's just that many programmers and languages are stuck without distinction between the two. $\endgroup$ Commented Sep 13, 2018 at 10:55
  • $\begingroup$ C or many other languages don't have iteration so we really should know what it is and how it works. Modern techniques sometimes are great but sometimes they are simply overcomplicated, less comprehensive compared to [i] and I don't think there is no kind of index accessing behind iterators - we just don't see it any more. So I doubt iterators are really faster than a simple [i]. $\endgroup$ Commented Sep 13, 2018 at 11:07
  • $\begingroup$ C was deficient in that regard even in comparison with other languages of its time. And no, they're certainly not less comprehensive. You need to look at code with fresh eyes - a lot of the crazy doesn't seem crazy anymore when you get used to it. The thing about iterators is that any indexing is strictly an implementation detail - which allows you to give much more freedom to the code that's using them as an interface. If you pass an array, it will always be an array. If you pass an iterable, the implementation can do whatever fits - like using a linked list. $\endgroup$ Commented Sep 13, 2018 at 17:00
  • $\begingroup$ Iterators can easily be faster than pointers, and they can be slower than pointers. But they're definitely easier to understand and reason about, and they allow a lot of optimisations that simply aren't possible with "pointers to an array". Just consider something like map-reduce - it wouldn't be possible if people stuck to the idea that arrays are just a pointer to the first item in an array. Unsurprisingly, it came from the other side of the language spectrum - languages that value abstraction over micro-tweaks. $\endgroup$ Commented Sep 13, 2018 at 17:02