Mastering C++ Programming

Concurrency tasks

The concurrency support module supports a concept called task. A task is work that happens concurrently across threads. A concurrent task can be created using the packaged_task class. The packaged_task class conveniently connects the thread function, the corresponding promise, and feature objects.

Let's understand the use of packaged_task with a simple example. The following program gives us an opportunity to taste a bit of functional programming with lambda expressions and functions:

#include <iostream>#include <future>#include <promise>#include <thread>#include <functional>using namespace std;int main ( ) {     packaged_task<int (int, int)>        addTask ( [] ( int firstInput, int secondInput ) { return firstInput + secondInput; ...