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 Be sure that knowledge from this book won’t get outdated, as more and more Boost libraries become part of the C++ Standard.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

Writing metafunctions using simpler methods


Chapter 4, Compile-time Tricks, and Chapter 8, Metaprogramming, were devoted to metaprogramming. If you were trying to use techniques from those chapters, you may have noticed that writing a metafunction can take a lot of time. So, it may be a good idea to experiment with metafunctions using more user-friendly methods, such as C++11 constexpr, before writing a portable implementation.

In this recipe, we'll take a look at how to detect constexpr support.

Getting ready

The constexpr functions are functions that can be evaluated at compile-time. That is all we need to know for this recipe.

How to do it...

Let's see how we can detect compiler support for the constexpr feature:

  1. Just like in other recipes from this chapter, we start with the following header:
#include <boost/config.hpp> 
  1. Write the constexpr function:
#if !defined(BOOST_NO_CXX11_CONSTEXPR) \
    && !defined(BOOST_NO_CXX11_HDR_ARRAY)

template <class T>
constexpr int get_size...