具有相同参数的 C++ std::sort

Question

I'm reading someone else's code, and I see something like this:

sort(myvec.begin(),  myvec.begin());

I wrote some code to test it, and it seems to do the same thing as

sort(myvec.begin(),  myvec.end());

Do they really do the same thing? Is that documented? Is there a way to understand why, or was it just an arbitrary choice to implement it in that way?

Update after answers

Yes, it's a no-op. My test code had a bug.

Answer 1

The code

sort(myvec.begin(),  myvec.begin());

should be a no-op, since that's an empty range. The code

sort(myvec.begin(),  myvec.end());

will sort the entire contents of myvec . If these happen to do the same thing, it means that your vector was already sorted. The first line is almost certainly a typo or a bug waiting to happen.

Answer 2

Iterators are just a way of specifying range. You must have bad intuitions about them if you have even thought that this code could work properly. What if we used method that takes 2 indices -> begin index of the part of vector being sorted and the index indicating end of it. Would sort(0, myvec.size()) and sort(0, 0) be equivalent?

This code should undoubtly be sort(myvec.begin(), myvec.end());