tests that permutations doesn't copy/move elems
tests that permutations doesn't copy/move elems

which is worth paying attention to since it has to make
referenc_wrappers

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