std::stop_token Class

The std::stop_token is a class that provides a way to call off asynchronous operation requests. It is equivalent to a token that can be transferred through different program fragments, providing the ability to notify about the cancellation of an ongoing process. Interestingly, the std::stop_token objects are highly convenient as they can be easily moved and copied, without adding much burden to the system’s processing.

Syntax

stop_token token_name = token;

std::stop_token Member Methods

The two primary functions of the std::stop_token class are:

• stop_requested(): This function responds with a value of true when a cancellation request has been made, otherwise, it returns false.
• stop_possible(): This function returns true if the related std::stop_source object can be utilized to request a cancellation, otherwise it returns false.

C++20 has introduced the <stop_token> Header, presenting an alternative method for canceling asynchronous operations. A new class std::stop_token is provided by the <stop_token> header that allows for seamless communication of a termination request between two threads.

In this article, we will discuss the basics of <stop_token> and how to use it in C++20.