54   struct page_t  struct
56     void init0 () { v.clear (); }  in init0()
57     void init1 () { v.clear (0xFF); }  in init1()
59     unsigned int len () const  in len()
62     bool is_empty () const  in is_empty()
70     void add (hb_codepoint_t g) { elt (g) |= mask (g); }  in add()
71     void del (hb_codepoint_t g) { elt (g) &= ~mask (g); }  in del()
72     bool has (hb_codepoint_t g) const { return !!(elt (g) & mask (g)); }  in has()
74     void add_range (hb_codepoint_t a, hb_codepoint_t b)  in add_range()
91     bool is_equal (const page_t *other) const  in is_equal()
96     unsigned int get_population () const  in get_population()
104     bool next (hb_codepoint_t *codepoint) const  in next()
126     bool previous (hb_codepoint_t *codepoint) const  in previous()
148     hb_codepoint_t get_min () const  in get_min()
155     hb_codepoint_t get_max () const  in get_max()
163     typedef unsigned long long elt_t;
164     enum { PAGE_BITS = 512 };
167     static unsigned int elt_get_min (const elt_t &elt) { return hb_ctz (elt); }  in elt_get_min()
168     static unsigned int elt_get_max (const elt_t &elt) { return hb_bit_storage (elt) - 1; }  in elt_get_max()
170     typedef hb_vector_size_t<elt_t, PAGE_BITS / 8> vector_t;
172     enum { ELT_BITS = sizeof (elt_t) * 8 };
173     enum { ELT_MASK = ELT_BITS - 1 };
174     enum { BITS = sizeof (vector_t) * 8 };
175     enum { MASK = BITS - 1 };
178     elt_t &elt (hb_codepoint_t g) { return v[(g & MASK) / ELT_BITS]; }  in elt()
179     elt_t const &elt (hb_codepoint_t g) const { return v[(g & MASK) / ELT_BITS]; }  in elt()
180     elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & ELT_MASK); }  in mask()
182     vector_t v;