I found some code that dereferences end() from an iota_view.

I found some code that dereferences end() from an iota_view.

I want to combine std::views::split or std::views::lazy_split with std::ranges::count but I cannot get it to work.

Is there a way to sum a C++20 range other than iterating over it?

I am trying to define an iterator that iterates through a puzzle game board cells by a given starting cell and some link representing some kind of a connection between the cells. Below I provided a sample code with the same methods but a trivial implementation that potentially should iterate over the cells with the coordinates {0, 0}, {1, 1}, {2, 2}, {3, 3}, {4, 4}:

Several algorithms in std::ranges (such as count_if, find_if, sort, etc.) accept both a predicate and a projection.

I have the code below (also on compiler explorer) and I’m confused about why the const Range & versions don’t work. The compiler complains that std::range::begin (and end) don’t work.

So, I have different behaviour for range and non-range versions of less functor. That’s a minimal code example to reproduce the behaviour: