C++ Primer, Fifth Edition

Defining Overloaded Functions

Consider a database application with several functions to find a record based on name, phone number, account number, and so on. Function overloading lets us define a collection of functions, each named lookup, that differ in terms of how they do the search. We can call lookup passing a value of any of several types:

Record lookup(const Account&);  // find by AccountRecord lookup(const Phone&);    // find by PhoneRecord lookup(const Name&);     // find by NameAccount acct;Phone phone;Record r1 = lookup(acct);  // call version that takes an AccountRecord r2 = lookup(phone); // call version that takes a Phone

Here, all three functions share the same name, yet they are three distinct functions. The compiler uses the ...