# You are allowed to redistribute it and sell it, alone or is a part of
# another product.
-# Cartesian products on heterogeneous collections.
+# Memory-efficient Cartesian products on heterogeneous collections.
#
# This module is a proof-of-concept to propose memory-efficient views on collections.
#
#
# However, in Nit, there in no native *tuple* type.
# So we need a first building block, a pair.
+module cartesian
# A simple read-only pair of two elements `e` and `f`.
class Pair[E, F]