Iterator and Const Iterator Comparison

I managed to get hold of a copy of Scott Meyer's Effective STL. Originally printed in 2001, this book contains all sorts of insights that I'm slowly working my way through.

Item 26, "Prefer iterator to const_iterator" states that, in some implementations, you cannot compare an iterator to a const_iterator. I have a memory of doing this in the past, so fired up Visual Studio to check the current situation.

std::vector<int> vec;
std::vector<int>::iterator it = vec.begin();
std::vector<int>::const_iterator cit = vev.cbegin();

if(it == cit && cit == it)
   std::cout << "iterators equal" << std::endl;

This code compiles and runs as you would expect.

What about reverse_iterators? Conceivably you may wish to move front-to-back and back-to-front through a container, while checking that your iterators don't point to the same element.

If we add the following lines, the program will no longer compile:

std::vector<int>::reverse_iterator rit = vec.rbegin();

if(it == rit && rit == it) // Compile Error!
  std::cout << "iterators equal" << std::endl;

In summary, using Visual Studio 2019, C++ 14 standard, we can compare iterators to their const counterparts, but we cannot compare iterators to reverse iterators.