Book Image

Mastering the C++17 STL

By : Arthur O'Dwyer
Book Image

Mastering the C++17 STL

By: Arthur O'Dwyer

Overview of this book

Modern C++ has come a long way since 2011. The latest update, C++17, has just been ratified and several implementations are on the way. This book is your guide to the C++ standard library, including the very latest C++17 features. The book starts by exploring the C++ Standard Template Library in depth. You will learn the key differences between classical polymorphism and generic programming, the foundation of the STL. You will also learn how to use the various algorithms and containers in the STL to suit your programming needs. The next module delves into the tools of modern C++. Here you will learn about algebraic types such as std::optional, vocabulary types such as std::function, smart pointers, and synchronization primitives such as std::atomic and std::mutex. In the final module, you will learn about C++'s support for regular expressions and file I/O. By the end of the book you will be proficient in using the C++17 standard library to implement real programs, and you'll have gained a solid understanding of the library's own internals.
Table of Contents (13 chapters)

Infinite alternatives with std::any

To paraphrase Henry Ford, an object of type std::variant<A, B, C> can hold a value
of any type--as long as it's A, B, or C. But suppose we wanted to hold a value of truly any type? Perhaps our program will load plugins at runtime that might contain new types impossible to predict. We can't specify those types in a variant. Or perhaps we are in the "recursive data type" situation detailed in the preceding section.

For these situations, the C++17 standard library provides an algebraic-data-type version of "infinity": the type std::any. This is a sort of a container (see Chapter 4, The Container Zoo) for a single object of any type at all. The container may be empty, or it may contain an object. You can perform the following fundamental operations on an any object:

  • Ask if it currently holds an object
  • Put a new...