Book Image

C++20 STL Cookbook

By : Bill Weinman
Book Image

C++20 STL Cookbook

By: Bill Weinman

Overview of this book

Fast, efficient, and flexible, the C++ programming language has come a long way and is used in every area of the industry to solve many problems. The latest version C++20 will see programmers change the way they code as it brings a whole array of features enabling the quick deployment of applications. This book will get you up and running with using the STL in the best way possible. Beginning with new language features in C++20, this book will help you understand the language's mechanics and library features and offer insights into how they work. Unlike other books, the C++20 STL Cookbook takes an implementation-specific, problem-solution approach that will help you overcome hurdles quickly. You'll learn core STL concepts, such as containers, algorithms, utility classes, lambda expressions, iterators, and more, while working on real-world recipes. This book is a reference guide for using the C++ STL with its latest capabilities and exploring the cutting-edge features in functional programming and lambda expressions. By the end of the book C++20 book, you'll be able to leverage the latest C++ features and save time and effort while solving tasks elegantly using the STL.
Table of Contents (13 chapters)

Share members of a managed object

The std::shared_ptr class provides an aliasing constructor to share a pointer managed by another unrelated pointer:

shared_ptr( shared_ptr<Y>&& ref, element_type* ptr ) noexcept;

This returns an aliased shared_ptr object that uses the resources of ref but returns a pointer to ptr. The use_count is shared with ref. The deleter is shared with ref. But get() returns ptr. This allows us to share a member of a managed object without sharing the entire object, and without allowing the entire object to be deleted while we're still using the member.

How to do it…

In this recipe, we create a managed object and share members of that object:

  • We start with a class for the managed object:
    struct animal {
        string name{};
        string sound{};
        animal(const string& n, const string& a)