Tuple Summary

The Tuple library brings the concept of tuples to C++. It is intuitive and concise, and although its primary use seems to be for multiple return value from functions, it is also very useful for creating all sorts of logical groupings such as storing sets of elements (as elements) in Standard Library containers. The alternative for achieving the same level of coherency is to create unique structs for every different return type (groupings), which is not only tedious work, it also removes the possibility of generic solutions for recurring tasks. These problems are alleviated with the use of the Boost.Tuple.

In this chapter, we've seen how to use the Tuple library and how to extend it in the form of function objects and algorithms that can work with any tuple. Accessing elements by index, and the get_head/get_tail member functions, provides consistency in working with tuples that enables many solutions that are impossible with other forms of user-defined types (UDTs).

The creator of Boost.Tuple, Jaakko Järvi, deserves credit for this great library. This creation goes a long way to prove that nearly anything lacking in C++ can be added through libraries by talented designers.