interator with ++ in c++

Question

Say, I have an iterator

vector<int> myVector;
vector<int>::iterator myIt;
for (myIt=myVector.begin(); myIt!=myVector.end(); ++myIt)
{

}

what if I use myIt++ instead of ++myIt.

I got this question, when I read How do I iterate over a Constant Vector? it says "Please read about prefix versus postfix increment operator. it++ should be ++it, and it++ is needed in rare cases (i.e. when erasing while iterating)." So, I am kind of confused

Thanks.

http://stackoverflow.com/questions/4706199/post-increment-and-pre-increment-within-a-for-loop-produce-same-output — Paddyd, Jan 13 '15 at 14:34
@Borgleader Depending on the iterator implementation and optimiser quality, performance might degrade a little bit. — Angew is no longer proud of SO, Jan 13 '15 at 14:34
there is a little difference, the post increment have to make a copy for the returned value — hidrargyro, Jan 13 '15 at 14:38
@Angew Semantically speaking: nothing changes. P.S: something something premature optimization, root of all evil, etc — Borgleader, Jan 13 '15 at 14:38
@Borgleader Then again, premature pesimization is probably worse. There is nothing to be lost by using pre-increment here, and possibly something to be gained. — juanchopanza, Jan 13 '15 at 14:47

score 1 · Accepted Answer · answered Jan 13 '15 at 14:35

1

In the context you use it, the result will be the same. However, the post-incerement and pre-increment operator are different things which basically can be implemented independently.

answered Jan 13 '15 at 14:35

Codor

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Let me clarify it. I got this question, when I read http://stackoverflow.com/questions/4890497/how-do-i-iterate-over-a-constant-vector it says "Please read about prefix versus postfix increment operator. it++ should be ++it, and it++ is needed in rare cases (i.e. when erasing while iterating)." So, I am kind of confused – user3440433 Jan 13 '15 at 14:41

interator with ++ in c++

1 Answers1