[iterators][closing_iterator] remove assignment operator (it is the
same as what the compiler would generate, so not need to provide it)
[iterators][ever_circling_iterator] remove assignment operator (it is
the same as what the compiler would generate, so no need to provide it)
[iterators][concate_iterator] remove templated assignment operator (it is not
really needed since the compiler constructed assignment operator and the
templated constructor, combined, do what this assignment operator does)
[iterators][segment_iterator] remove templated assignment operator from
range_segment_iterator class (it is not really needed since the compiler
constructed assignment operator and the templated constructor, combined,
do what this assignment operator does)
[iterators][flatten_iterator] re-write line in less than 80 characters;
remove templated assignment operator (it is not really needed since the assignment
operator defined and the templated constructor, combined, do what this assignment
operator does)
[iterators][flatten_iterator] change statement layout to be nicer
Merge pull request #173 from mkaravel/fix/assignment_operators_for_iterators

Fix/assignment operators for iterators