Book Image

C++ Fundamentals

By : Antonio Mallia, Francesco Zoffoli
Book Image

C++ Fundamentals

By: Antonio Mallia, Francesco Zoffoli

Overview of this book

C++ Fundamentals begins by introducing you to the C++ compilation model and syntax. You will then study data types, variable declaration, scope, and control flow statements. With the help of this book, you'll be able to compile fully working C++ code and understand how variables, references, and pointers can be used to manipulate the state of the program. Next, you will explore functions and classes — the features that C++ offers to organize a program — and use them to solve more complex problems. You will also understand common pitfalls and modern best practices, especially the ones that diverge from the C++98 guidelines. As you advance through the chapters, you'll study the advantages of generic programming and write your own templates to make generic algorithms that work with any type. This C++ book will guide you in fully exploiting standard containers and algorithms, understanding how to pick the appropriate one for each problem. By the end of this book, you will not only be able to write efficient code but also be equipped to improve the readability, performance, and maintainability of your programs.
Table of Contents (9 chapters)
C++ Fundamentals


variant is a value type that's used to represent a choice of types. The class takes a list of types, and the variant will be able to contain one value of any of those types.

It is often referred to as tagged union, because similar to a union, it can store multiple types, with only one present at a time. It also keeps track of which type is currently stored.

During the execution of a program, variant will contain exactly one of the possible types at a time.

Like optional, variant is a value type: when we create a copy of variant, the element that is currently stored is copied into the new variant.

To interact with std::variant, the C++ standard library gives us two main functions:

  • holds_alternative<Type>(variant): It returns true if the variant is currently holding the provided type, if not then false.

  • get(variant): There are two versions: get<Type>(variant) and get<Index>(variant).

get<Type>(variant) gets the value of the type that's currently stored inside...