makes sure cycle doesn't copy or move elements
makes sure cycle doesn't copy or move elements

ryanhaining/cppitertools,ryanhaining/cppitertools,jkhoogland/cppitertools,ryanhaining/cppitertools,jkhoogland/cppitertools,jkhoogland/cppitertools,tempbottle/cppitertools,tempbottle/cppitertools,tempbottle/cppitertools