[iter] Separate hb_iota implementation from hb_range

This commit is contained in:
Behdad Esfahbod 2019-08-30 11:59:50 -05:00
parent 814dc3cbe5
commit ce4d63beec
1 changed files with 27 additions and 2 deletions

View File

@ -654,11 +654,36 @@ struct
}
HB_FUNCOBJ (hb_range);
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, S step) : v (start), 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 true; }
unsigned __len__ () const { return UINT_MAX; }
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 { return hb_iota_iter_t (v, step); }
bool operator != (const hb_iota_iter_t& o) const { return true; }
private:
T v;
S step;
};
struct
{
template <typename T = unsigned, typename S = unsigned> hb_range_iter_t<T, S>
template <typename T = unsigned, typename S = unsigned> hb_iota_iter_t<T, S>
operator () (T start = 0u, S&& step = 1u) const
{ return hb_range_iter_t<T, S> (start, step >= 0 ? hb_int_max (T) : hb_int_min (T), step); }
{ return hb_iota_iter_t<T, S> (start, step); }
}
HB_FUNCOBJ (hb_iota);