Changes filter.hpp to be subclassed
Changes filter.hpp to be subclassed

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