Book Image

Modern C++ Programming Cookbook

By : Marius Bancila
Book Image

Modern C++ Programming Cookbook

By: Marius Bancila

Overview of this book

C++ is one of the most widely used programming languages. Fast, efficient, and flexible, it is used to solve many problems. The latest versions of C++ have seen programmers change the way they code, giving up on the old-fashioned C-style programming and adopting modern C++ instead. Beginning with the modern language features, each recipe addresses a specific problem, with a discussion that explains the solution and offers insight into how it works. You will learn major concepts about the core programming language as well as common tasks faced while building a wide variety of software. You will learn about concepts such as concurrency, performance, meta-programming, lambda expressions, regular expressions, testing, and many more in the form of recipes. These recipes will ensure you can make your applications robust and fast. By the end of the book, you will understand the newer aspects of C++11/14/17 and will be able to overcome tasks that are time-consuming or would break your stride while developing.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Using std::conditional to choose between types


In the previous recipes, we have looked at some of the features from the type support library, and particularly type traits. Related topics have been discussed in other parts of the book, such as using std::enable_if to hide function overloads, in Chapter 4, Preprocessor and Compilation, and std::decay to remove const and volatile qualifiers, when we discussed visiting variants, also in this chapter. Another type transformation feature worth discussing to a larger extent is std::conditional that enables us to choose between two types at compile time, based on a compile-time Boolean expression. From this recipe, you will learn how it works and how to use it through several examples.

Getting ready

It is recommended that you first read the Using type traits to query properties of types recipe of this chapter.

How to do it...

The following is a list of examples that show how to use std::conditional (and std::conditional_t) to choose at compile time...