tests imap(filter(imap()))
tests imap(filter(imap()))

Currently a problem with modifying function

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