C Interfaces and Implementations: Techniques for Creating Reusable Software

Chapter 9. Sets

A set is an unordered collection of distinct members. The basic operations on a set are testing for membership, adding members, and removing members. Other operations include set union, intersection, difference, and symmetric difference. Given two sets s and t, the union s + t is a set that contains everything in s and everything in t; the intersection s * t is the set whose members appear in both s and t, the difference s - t is the set whose members appear in s but not in t, and the symmetric difference, often written as s / t, is the set whose members appear in only one of s or t.

Sets are usually described in terms of a universe — the set of all possible members. For example, sets of characters are usually associated with the ...