Book Image

Modern C++: Efficient and Scalable Application Development

By : Richard Grimes, Marius Bancila
Book Image

Modern C++: Efficient and Scalable Application Development

By: Richard Grimes, Marius Bancila

Overview of this book

C++ is one of the most widely used programming languages. It is fast, flexible, and used to solve many programming problems. This Learning Path gives you an in-depth and hands-on experience of working with C++, using the latest recipes and understanding most recent developments. You will explore C++ programming constructs by learning about language structures, functions, and classes, which will help you identify the execution flow through code. You will also understand the importance of the C++ standard library as well as memory allocation for writing better and faster programs. Modern C++: Efficient and Scalable Application Development deals with the challenges faced with advanced C++ programming. You will work through advanced topics such as multithreading, networking, concurrency, lambda expressions, and many more recipes. By the end of this Learning Path, you will have all the skills to become a master C++ programmer. This Learning Path includes content from the following Packt products: • Beginning C++ Programming by Richard Grimes • Modern C++ Programming Cookbook by Marius Bancila • The Modern C++ Challenge by Marius Bancila
Table of Contents (24 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
12
Math Problems
13
Language Features
14
Strings and Regular Expressions
15
Streams and Filesystems
16
Date and Time
17
Algorithms and Data Structures
Index

Function pointers


When an application is run, the functions it will call will exist in memory somewhere. This means that you can get the address of a function. C++ allows you to use the function call operator (a pair of parentheses enclosing the parameters ()) to call a function through a function pointer.

Remember the parentheses!

First, a simple example of how function pointers can cause difficult to notice bugs in your code. A global function called get_status performs various validation actions to determine if the state of the system is valid. The function returns a value of zero to mean that the system state is valid and values over zero are error codes:

    // values over zero are error codes 
    int get_status() 
    { 
        int status = 0;  
        // code that checks the state of data is valid 
        return status; 
    }

The code could be called like this:

    if (get_status > 0) 
    { 
        cout << "system state is invalid" << endl; 
    }

This is an error...