C++ Primer, Fifth Edition

12.3.2. Defining the Query Program Classes

We’ll start by defining our TextQuery class. The user will create objects of this class by supplying an istream from which to read the input file. This class also provides the query operation that will take a string and return a QueryResult representing the lines on which that string appears.

The data members of the class have to take into account the intended sharing with QueryResult objects. The QueryResult class will share the vector representing the input file and the sets that hold the line numbers associated with each word in the input. Hence, our class has two data members: a shared_ptr to a dynamically ...