}
HB_FUNCOBJ (hb_apply);
+/* hb_iota() */
+
+template <typename T, typename S>
+struct hb_iota_iter_t :
+ hb_iter_t<hb_iota_iter_t<T, S>, T>
+{
+ hb_iota_iter_t (T start, T end, S step) : v (start), end (end_for (start, end, step)), step (step) {}
+
+ typedef T __item_t__;
+ static constexpr bool is_random_access_iterator = true;
+ static constexpr bool is_sorted_iterator = true;
+ __item_t__ __item__ () const { return v; }
+ __item_t__ __item_at__ (unsigned j) const { return v + j * step; }
+ bool __more__ () const { return v != end; }
+ unsigned __len__ () const { return (end - v) / step; }
+ void __next__ () { v += step; }
+ void __forward__ (unsigned n) { v += n * step; }
+ void __prev__ () { v -= step; }
+ void __rewind__ (unsigned n) { v -= n * step; }
+ hb_iota_iter_t __end__ () const { hb_iota_iter_t (end, end, step); }
+ bool operator != (const hb_iota_iter_t& o) const
+ { return v != o.v || end != o.end || step != o.step; }
+
+ private:
+ static inline T end_for (T start, T end, S step)
+ {
+ auto res = (end - start) % step;
+ if (!res)
+ return end;
+ end += step - res;
+ return end;
+ }
+
+ private:
+ T v;
+ T end;
+ S step;
+};
+struct
+{
+ template <typename T = unsigned> hb_iota_iter_t<T, unsigned>
+ operator () (T end = (unsigned) -1) const
+ { return hb_iota_iter_t<T, unsigned> (0, end, 1u); }
+
+ template <typename T, typename S = unsigned> hb_iota_iter_t<T, S>
+ operator () (T start, T end, S&& step = 1u) const
+ { return hb_iota_iter_t<T, S> (start, end, step); }
+}
+HB_FUNCOBJ (hb_iota);
+
+
/* hb_sink() */
template <typename Sink>
long vl;
s >> vl;
+ hb_iota ();
+ assert (hb_iota (9).len () == 9);
+ assert (hb_iota (2, 9).len () == 7);
+ assert (hb_iota (2, 9, 3).len () == 3);
+ assert (hb_iota (2, 8, 3).len () == 2);
+ assert (hb_iota (2, 7, 3).len () == 2);
+ assert (hb_iota (-2, -9, -3).len () == 3);
+ assert (hb_iota (-2, -8, -3).len () == 2);
+ assert (hb_iota (-2, -7, -3).len () == 2);
+
return 0;
}