Pairs of objects occur repeatedly in programming, most often to denote 2d coordinates, an association between two objects, or simply a logical grouping. Since it is such a fundamental data structure, and because it is also something to which many data structures simplify to, a pair of objects can be found in various guises even inside the same library. In Pastel, a pair can be given as a std::pair, or a Tuple. Thus a concept map is needed to map the syntactically different types to a uniform concept. This concept map is called the As_Pair.