Beyond the C++ Standard Library: An Introduction to Boost [Electronic resources] نسخه متنی

Signals Summary

Use Signals when

You need robust callbacks

There can be multiple handlers of events

The connection between the signal and the connected slots should be configurable at runtime

That Boost.Signals supersedes old-style callbacks should be blatantly clear by now, and this library is one of the best signals and slots implementations available. The design pattern that the library captures is well known and has been studied for a long time, so the domain is mature. Some programming languages already have such mechanisms available directly in the languagefor example, delegates and events in .NET. In C++, the problem is elegantly solved with libraries. Signals and slots are used to separate the trigger mechanism of an event from the code that handles it. This separation decouples subsystems and makes them more comprehensible. It also solves the problem of updating multiple interested parties when important events take place. There are numerous places in a typical program or library where signals and slots are useful. Whether you are writing a GUI framework or an intrusion detection system for a power plant, Signals is ready to take care of all your signaling needs. It is easy to learn how to use, yet it also offers the advanced functionality that is required for complex tasks. For example, custom Combiners make it possible to write event mechanisms that are tailor-made for a certain domain.

Boost.Signals was written by Douglas Gregor (who incidentally also wrote Boost.Function). This is a great library; thank you Doug!