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

Defining Function and Class Templates

In the previous section, we saw the advantages of templates in writing abstractions. In this section, we are going to explore how we can effectively use templates in our code to create templated functions and templated classes.

Function Template

In the previous section, we learned how function templates are written.

In this section, we will learn about the two features that were introduced by C++11 that make it easier to write template functions. These two functions are trailing return types and decltype.

Let's start with the decltype. The decltype is a keyword that accepts an expression and returns the type of that expression. Let's examine the following code:

int x;
decltype(x) y;

In the previous code, y is declared as an integer, because we are using the type of the expression x, which is int.

Any expression can be used inside decltype, even complex ones, for example:

User user;
decltype(user.getAccount()) account;

Let's look at the second feature—trailing...