boostpromise

boostpromise is a C++ library that provides an implementation of the Promises/A+ specification for asynchronous programming. It aims to simplify the management of asynchronous operations by allowing developers to chain callbacks and handle errors in a more structured and readable manner. Unlike traditional callback-based approaches, which can lead to deeply nested and difficult-to-maintain code (often referred to as "callback hell"), boostpromise offers a linear and compositional way to write asynchronous code.

The core concept in boostpromise is the "future" object, which represents a value that may not be available yet. Operations that produce a future can be initiated, and then subsequent operations can be attached to this future to be executed when the value becomes available. This attachment is typically done using methods like `then()`, which takes success and error handlers as arguments. The `then()` method itself returns another future, enabling the chaining of multiple asynchronous operations into a sequence.

boostpromise supports common asynchronous patterns such as parallel execution and waiting for multiple futures. It provides mechanisms for creating futures from various sources, including standard library functions, Boost.Asio operations, and custom asynchronous tasks. Error handling is a first-class citizen, with a clear separation between successful results and exceptions, which are propagated through the promise chain. The library is designed to be header-only, making it easy to integrate into existing C++ projects. It emphasizes clarity, robustness, and a developer-friendly API for managing the complexities of asynchronous programming.