In Sean Parent's CppCon keynote last week, he went through the process of implementing an algorithm he called "sort_subrange", which takes four iterators describing two ranges, one a subset of the other, and sorts the subrange - as if you had sorted the entire range. (See https://www.youtube.com/watch?v=sWgDk-o-6ZE, starting at about 31:30). I have implemented this in Boost.Algorithm (crediting Sean) - called partition_sort. However, while I was doing this, I thought of a different algorithm; one that gathered all the elements into the subrange as if the entire range was sorted, but didn't actually do the sorting. I've implemented that one, too - but I'm having a bit of trouble coming up with a name. I've used "partition_subrange", but that not that clear. Sean has suggested "elements_in_subrange" and "elements_within_subrange". Here's the declaration: template<typename Iterator, typename Pred> void partition_subrange ( Iterator first, Iterator last, Iterator sub_first, Iterator sub_last, Pred p) /// \brief Gather the elements of the subrange [sub_first, sub_last) that is /// inside the range [first, last) as if you had sorted the entire range. Any suggestions? -- Marshall