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

Being Generic in Templates

So far, we have learned how the compiler can make our templated functions easier to use by automatically deducing the types used. The template code decides whether to accept a parameter as a value or a reference, and the compiler finds the type for us. But what do we do if we want to be agnostic regarding whether an argument is a value or a reference, and we want to work with it regardless?

An example would be std::invoke in C++17. std::invoke is a function that takes a function as the first argument, followed by a list of arguments, and calls the function with the arguments. For example:

void do_action(int, float, double);
double d = 1.5;
std::invoke(do_action, 1, 1.2f, d);

Similar examples would apply if you wanted to log before calling a function, or you wanted to execute the function in a different thread, such as std::async does.

Let's demystify the difference by using the following code:

struct PrintOnCopyOrMove {
  PrintOnCopyOrMove(std::string name) : _name...