Book Image

Modern C++ Programming Cookbook - Third Edition

By : Marius Bancila
Book Image

Modern C++ Programming Cookbook - Third Edition

By: Marius Bancila

Overview of this book

The updated third edition of Modern C++ Programming Cookbook addresses the latest features of C++23, such as the stack library, the expected and mdspan types, span buffers, formatting library improvements, and updates to the ranges library. It also gets into more C++20 topics not previously covered, such as sync output streams and source_location. The book is organized in the form of practical recipes covering a wide range of real-world problems. It gets into the details of all the core concepts of modern C++ programming, such as functions and classes, iterators and algorithms, streams and the file system, threading and concurrency, smart pointers and move semantics, and many others. You will cover the performance aspects of programming in depth, and learning to write fast and lean code with the help of best practices. You will explore useful patterns and the implementation of many idioms, including pimpl, named parameter, attorney-client, and the factory pattern. A chapter dedicated to unit testing introduces you to three of the most widely used libraries for C++: Boost.Test, Google Test, and Catch2. By the end of this modern C++ programming book, you will be able to effectively leverage the features and techniques of C++11/14/17/20/23 programming to enhance the performance, scalability, and efficiency of your applications.
Table of Contents (15 chapters)
13
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14
Index

Using std::conditional to choose between types

In the previous recipes, we looked at some of the features from the type support library, and type traits in particular. Related topics have been discussed in other parts of this book, such as using std::enable_if to hide function overloads in Chapter 4, Preprocessing 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, which enables us to choose between two types at compile time, based on a compile-time Boolean expression. In 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, earlier in this chapter.

How to do it...

The following is a list of examples that show you how to use std::conditional (and std::conditional_t...