A tuple is a template that is similar to a
pair (§ 11.2.3, p. 426). Each
pair type has different types for its members, but every
pair always has exactly two members. A
tuple also has members whose types vary from one
tuple type to another, but a
tuple can have any number of members. Each distinct
tuple type has a fixed number of members, but the number of members in one
tuple type can differ from the number of members in another.
tuple is most useful when we want to combine some data into a single object but do not want to bother to define a data structure to represent those data. Table 17.1 lists the operations that ...