Book Image

Boost C++ Application Development Cookbook - Second Edition

By : Anton Polukhin Alekseevic
Book Image

Boost C++ Application Development Cookbook - Second Edition

By: Anton Polukhin Alekseevic

Overview of this book

If you want to take advantage of the real power of Boost and C++ and avoid the confusion about which library to use in which situation, then this book is for you. Beginning with the basics of Boost C++, you will move on to learn how the Boost libraries simplify application development. You will learn to convert data such as string to numbers, numbers to string, numbers to numbers and more. Managing resources will become a piece of cake. You’ll see what kind of work can be done at compile time and what Boost containers can do. You will learn everything for the development of high quality fast and portable applications. Write a program once and then you can use it on Linux, Windows, MacOS, Android operating systems. From manipulating images to graphs, directories, timers, files, networking – everyone will find an interesting topic. Be sure that knowledge from this book won’t get outdated, as more and more Boost libraries become part of the C++ Standard.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Formatting strings using safe printf-like functions


The printf family of functions is a threat to security. It is a very bad design to allow users to put their own strings as a type and format the specifiers. So what do we do when user-defined format is required? How shall we implement the std::string to_string(const std::string& format_specifier) const; member function of the following class?

class i_hold_some_internals 
{
    int i;
    std::string s;
    char c;
    // ...
}; 

Getting ready

Basic knowledge of standard library is more than enough for this recipe.

How to do it...

We wish to allow users to specify their own output format for a string:

  1. To do that in a safe manner, we need the following header:
#include <boost/format.hpp>
  1. Now, we add some comments for the user:
    // `fmt` parameter may contain the following:
    // $1$ for outputting integer 'i'.
    // $2$ for outputting string 's'.
    // $3$ for outputting character 'c'.
    std::string to_string(const std::string&amp...