c-resources/CPlusPlus20ForProgrammers-m.../examples/ch20/fig20_09-13/Author.cpp

49 lines
2.0 KiB
C++
Raw Normal View History

2024-04-09 06:45:18 +00:00
// Fig. 20.11: Author.cpp
// Author member-function definitions.
#include <fmt/format.h>
#include <iostream>
#include <memory>
#include <string>
#include <string_view>
#include "Author.h"
#include "Book.h"
Author::Author(std::string_view authorName) : name(authorName) {}
Author::~Author() {
std::cout << fmt::format("Destroying Author: {}\n", name);
}
// print the title of the Book this Author wrote
void Author::printBookTitle() {
// if weakBookPtr.lock() returns a non-empty shared_ptr
if (std::shared_ptr<Book> bookPtr{weakBookPtr.lock()}) {
// show the reference count increase and print the Book's title
std::cout << fmt::format("Reference count for Book {} is {}\n",
bookPtr->title, bookPtr.use_count());
std::cout << fmt::format("Author {} wrote the book {}\n",
name, bookPtr->title);
}
else { // weakBookPtr points to NULL
std::cout << "This Author has no Books.\n";
}
}
/**************************************************************************
* (C) Copyright 1992-2022 by Deitel & Associates, Inc. and *
* Pearson Education, Inc. All Rights Reserved. *
* *
* DISCLAIMER: The authors and publisher of this book have used their *
* best efforts in preparing the book. These efforts include the *
* development, research, and testing of the theories and programs *
* to determine their effectiveness. The authors and publisher make *
* no warranty of any kind, expressed or implied, with regard to these *
* programs or to the documentation contained in these books. The authors *
* and publisher shall not be liable in any event for incidental or *
* consequential damages in connection with, or arising out of, the *
* furnishing, performance, or use of these programs. *
**************************************************************************/