Functions having a long list of arguments such as:
void retrieve(const string& title, const string& author, int ISBN, int year, bool& inStore); can become a maintenance problem, since their argument list is likely to be changed in the future. For example, a URL with a book cover image may be added or other arguments may be omitted. Consequently, every occurrence of a function call has to be modified appropriately. A better solution is to pack the entire argument list in a single struct and pass it by reference (or by address in C) to the function:
struct Item{string title;string author; int ISBN; int year, bool inStore };void retrieve(Item& book);The advantages of this technique are obvious:
1. Maintenance. Every modification will be localized to the definition of the struct, but no other code modifications will be required.
2. Performance. Since a reference is all that has to be passed to the called function, you may gain a slight performance boost.
3. Future extensibility. A struct can serve as a base for other classes. It may be extended to have member functions as well.
