lst-0004-book.cpp
// https://godbolt.org/z/Tq9xbGxs4
struct Book {
auto getTitle() { return Title{"The C++ Handbook"s}; }
auto getAuthor() { return Author{"Torsten T. Will"s}; }
auto turnPage() { return /* Reference to the next page */ 42; }
auto getPage() { return "current page content"; }
auto getLocation() { return /* Shelf number/Book number */ 73; }
};
struct BookFinder {
Catalog catalog;
auto find(Book& book) { /* Shelf number/Book number */
catalog.findBookBy(book.getTitle(), book.getAuthor());
}
};