Book Image

C++ Reactive Programming

By : Praseed Pai, Peter Abraham
Book Image

C++ Reactive Programming

By: Praseed Pai, Peter Abraham

Overview of this book

Reactive programming is an effective way to build highly responsive applications with an easy-to-maintain code base. This book covers the essential functional reactive concepts that will help you build highly concurrent, event-driven, and asynchronous applications in a simpler and less error-prone way. C++ Reactive Programming begins with a discussion on how event processing was undertaken by different programming systems earlier. After a brisk introduction to modern C++ (C++17), you’ll be taken through language-level concurrency and the lock-free programming model to set the stage for our foray into the Functional Programming model. Following this, you’ll be introduced to RxCpp and its programming model. You’ll be able to gain deep insights into the RxCpp library, which facilitates reactive programming. You’ll learn how to deal with reactive programming using Qt/C++ (for the desktop) and C++ microservices for the Web. By the end of the book, you will be well versed with advanced reactive programming concepts in modern C++ (C++17).
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Writing basic RxCpp custom operators


In the previous section, we covered the topic of operator chaining. Operator chaining was possible because, the stock operators are implemented as part of the observable<T> type. The operators that we are going to implement initially cannot be part of the operator chaining strategy. In this section, we will implement some RxCpp operators that can transform an Observable and return another Observable.

Writing an RxCpp operator as a function

To kickstart the discussion, let's write a simple operator that works on observable<string>. The operator just prepends the literal text Hello before each item in the stream:

//----------- operatorSimple.cpp 
#include "rxcpp/rx.hpp" 
#include "rxcpp/rx-test.hpp" 
#include <iostream> 
namespace rxu=rxcpp::util; 
#include <array> 
using namespace rxcpp; 
using namespace rxcpp::operators; 
// Write a Simple Reactive operator Takes an Observable<string> and 
// Prefix Hello to every item and return...