Use Set to Sort and Filter User Input

The set container is an associative container where each element is a single value, which is used as the key. Elements in a set are maintained in sorted order and duplicate keys are not allowed. The set container is often misunderstood, and it does have fewer and more specific uses than more general containers such as vector and map. One common use for a set is to filter duplicates from a set of values.

How to do it

In this recipe we will read words from the standard input and filter out the duplicates.

• We'll start by defining an alias for an istream iterator. We'll use this to get input from the command line.