In the concurrent world, a Future object refers to an object whose actual value is to be computed in the future. You can think of it as a handle to an asynchronous invocation of a computation that yields a value.
Many so called concurrent programming languages support this idea as a native construct offered by the core language itself. Unfortunately, C++ does not. Well, at least not in the current standard; C++0x (or shall I say C++1x ?) is going to support std::future as part of the massive new C++0x thread library, which is based on boost::thread. In this post we will implement a simple, yet very powerful, such future object.