Ranges, Part 2: Iterable Range Adaptors, Algorithms, and Composition

摘要

STL introduced a wonderfully novel idea — separating algorithms from the containers. Thus, iterators were born, and yes, they have proven to be of great use. However, if you try to use them in nontriv-ial cases such as iterator composition (say to filter a vector, transform each resulting element, and then use it), they become hard to use. Moreover, when you use iterators in algorithms, you always have to specify some_array.begin() and some_array.end(). This can be tedious and makes code much less readable. Furthermore, when you code manual loops, again, the code is verbose, error prone, spans over multiple lines, and is hard to read. But don't worry — ranges are here to help!