Branch
Hash :
2ce548a7
Author :
Date :
2025-10-13T15:11:15
Clean up std::forward to match spelling of argument type (#5608) This helps readability and also avoids false positives during static analysis.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
/*
* Copyright © 2018 Google, Inc.
* Copyright © 2019 Facebook, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
* Facebook Author(s): Behdad Esfahbod
*/
#ifndef HB_ITER_HH
#define HB_ITER_HH
#include "hb.hh"
#include "hb-algs.hh"
#include "hb-meta.hh"
/* Unified iterator object.
*
* The goal of this template is to make the same iterator interface
* available to all types, and make it very easy and compact to use.
* hb_iter_tator objects are small, light-weight, objects that can be
* copied by value. If the collection / object being iterated on
* is writable, then the iterator returns lvalues, otherwise it
* returns rvalues.
*
* If iterator implementation implements operator!=, then it can be
* used in range-based for loop. That already happens if the iterator
* is random-access. Otherwise, the range-based for loop incurs
* one traversal to find end(), which can be avoided if written
* as a while-style for loop, or if iterator implements a faster
* __end__() method. */
/*
* Base classes for iterators.
*/
/* Base class for all iterators. */
template <typename iter_t, typename Item = typename iter_t::__item_t__>
struct hb_iter_t
{
typedef Item item_t;
constexpr unsigned get_item_size () const { return hb_static_size (Item); }
static constexpr bool is_iterator = true;
static constexpr bool is_random_access_iterator = false;
static constexpr bool is_sorted_iterator = false;
static constexpr bool has_fast_len = false; // Should be checked in combination with is_random_access_iterator.
private:
/* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */
const iter_t* thiz () const { return static_cast<const iter_t *> (this); }
iter_t* thiz () { return static_cast< iter_t *> (this); }
public:
/* Operators. */
iter_t iter () const { return *thiz(); }
iter_t operator + () const { return *thiz(); }
iter_t _begin () const { return *thiz(); }
iter_t begin () const { return _begin (); }
iter_t _end () const { return thiz()->__end__ (); }
iter_t end () const { return _end (); }
explicit operator bool () const { return thiz()->__more__ (); }
unsigned len () const { return thiz()->__len__ (); }
/* The following can only be enabled if item_t is reference type. Otherwise
* it will be returning pointer to temporary rvalue. */
template <typename T = item_t,
hb_enable_if (std::is_reference<T>::value)>
hb_remove_reference<item_t>* operator -> () const { return std::addressof (**thiz()); }
item_t operator * () const { return thiz()->__item__ (); }
item_t operator * () { return thiz()->__item__ (); }
item_t operator [] (unsigned i) const { return thiz()->__item_at__ (i); }
item_t operator [] (unsigned i) { return thiz()->__item_at__ (i); }
iter_t& operator += (unsigned count) & { thiz()->__forward__ (count); return *thiz(); }
iter_t operator += (unsigned count) && { thiz()->__forward__ (count); return *thiz(); }
iter_t& operator ++ () & { thiz()->__next__ (); return *thiz(); }
iter_t operator ++ () && { thiz()->__next__ (); return *thiz(); }
iter_t& operator -= (unsigned count) & { thiz()->__rewind__ (count); return *thiz(); }
iter_t operator -= (unsigned count) && { thiz()->__rewind__ (count); return *thiz(); }
iter_t& operator -- () & { thiz()->__prev__ (); return *thiz(); }
iter_t operator -- () && { thiz()->__prev__ (); return *thiz(); }
iter_t operator + (unsigned count) const { auto c = thiz()->iter (); c += count; return c; }
friend iter_t operator + (unsigned count, const iter_t &it) { return it + count; }
iter_t operator ++ (int) { iter_t c (*thiz()); ++*thiz(); return c; }
iter_t operator - (unsigned count) const { auto c = thiz()->iter (); c -= count; return c; }
iter_t operator -- (int) { iter_t c (*thiz()); --*thiz(); return c; }
template <typename T>
iter_t& operator >> (T &v) & { v = **thiz(); ++*thiz(); return *thiz(); }
template <typename T>
iter_t operator >> (T &v) && { v = **thiz(); ++*thiz(); return *thiz(); }
template <typename T>
iter_t& operator << (const T v) & { **thiz() = v; ++*thiz(); return *thiz(); }
template <typename T>
iter_t operator << (const T v) && { **thiz() = v; ++*thiz(); return *thiz(); }
protected:
hb_iter_t () = default;
hb_iter_t (const hb_iter_t &o HB_UNUSED) = default;
hb_iter_t (hb_iter_t &&o HB_UNUSED) = default;
hb_iter_t& operator = (const hb_iter_t &o HB_UNUSED) = default;
hb_iter_t& operator = (hb_iter_t &&o HB_UNUSED) = default;
};
#define HB_ITER_USING(Name) \
using item_t = typename Name::item_t; \
using Name::_begin; \
using Name::begin; \
using Name::_end; \
using Name::end; \
using Name::get_item_size; \
using Name::is_iterator; \
using Name::iter; \
using Name::operator bool; \
using Name::len; \
using Name::operator ->; \
using Name::operator *; \
using Name::operator []; \
using Name::operator +=; \
using Name::operator ++; \
using Name::operator -=; \
using Name::operator --; \
using Name::operator +; \
using Name::operator -; \
using Name::operator >>; \
using Name::operator <<; \
static_assert (true, "")
/* Returns iterator / item type of a type. */
template <typename Iterable>
using hb_iter_type = decltype (hb_deref (hb_declval (Iterable)).iter ());
template <typename Iterable>
using hb_item_type = decltype (*hb_deref (hb_declval (Iterable)).iter ());
template <typename> struct hb_array_t;
template <typename> struct hb_sorted_array_t;
struct
{
template <typename T> hb_iter_type<T>
operator () (T&& c) const
{ return hb_deref (std::forward<T> (c)).iter (); }
/* Specialization for C arrays. */
template <typename Type> inline hb_array_t<Type>
operator () (Type *array, unsigned int length) const
{ return hb_array_t<Type> (array, length); }
template <typename Type, unsigned int length> hb_array_t<Type>
operator () (Type (&array)[length]) const
{ return hb_array_t<Type> (array, length); }
}
HB_FUNCOBJ (hb_iter);
struct
{
template <typename T> auto
impl (T&& c, hb_priority<1>) const HB_RETURN (unsigned, c.len ())
template <typename T> auto
impl (T&& c, hb_priority<0>) const HB_RETURN (unsigned, c.len)
public:
template <typename T> auto
operator () (T&& c) const HB_RETURN (unsigned, impl (std::forward<T> (c), hb_prioritize))
}
HB_FUNCOBJ (hb_len);
/* Mixin to fill in what the subclass doesn't provide. */
template <typename iter_t, typename item_t = typename iter_t::__item_t__>
struct hb_iter_fallback_mixin_t
{
private:
/* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */
const iter_t* thiz () const { return static_cast<const iter_t *> (this); }
iter_t* thiz () { return static_cast< iter_t *> (this); }
public:
/* Access: Implement __item__(), or __item_at__() if random-access. */
item_t __item__ () const { return (*thiz())[0]; }
item_t __item_at__ (unsigned i) const { return *(*thiz() + i); }
/* Termination: Implement __more__(), or __len__() if random-access. */
bool __more__ () const { return bool (thiz()->len ()); }
unsigned __len__ () const
{ iter_t c (*thiz()); unsigned l = 0; while (c) { c++; l++; } return l; }
/* Advancing: Implement __next__(), or __forward__() if random-access. */
void __next__ () { *thiz() += 1; }
void __forward__ (unsigned n) { while (*thiz() && n--) ++*thiz(); }
/* Rewinding: Implement __prev__() or __rewind__() if bidirectional. */
void __prev__ () { *thiz() -= 1; }
void __rewind__ (unsigned n) { while (*thiz() && n--) --*thiz(); }
/* Range-based for: Implement __end__() if can be done faster,
* and operator!=. */
iter_t __end__ () const
{
if (thiz()->is_random_access_iterator)
return *thiz() + thiz()->len ();
/* Above expression loops twice. Following loops once. */
auto it = *thiz();
while (it) ++it;
return it;
}
protected:
hb_iter_fallback_mixin_t () = default;
hb_iter_fallback_mixin_t (const hb_iter_fallback_mixin_t &o HB_UNUSED) = default;
hb_iter_fallback_mixin_t (hb_iter_fallback_mixin_t &&o HB_UNUSED) = default;
hb_iter_fallback_mixin_t& operator = (const hb_iter_fallback_mixin_t &o HB_UNUSED) = default;
hb_iter_fallback_mixin_t& operator = (hb_iter_fallback_mixin_t &&o HB_UNUSED) = default;
};
template <typename iter_t, typename item_t = typename iter_t::__item_t__>
struct hb_iter_with_fallback_t :
hb_iter_t<iter_t, item_t>,
hb_iter_fallback_mixin_t<iter_t, item_t>
{
protected:
hb_iter_with_fallback_t () = default;
hb_iter_with_fallback_t (const hb_iter_with_fallback_t &o HB_UNUSED) = default;
hb_iter_with_fallback_t (hb_iter_with_fallback_t &&o HB_UNUSED) = default;
hb_iter_with_fallback_t& operator = (const hb_iter_with_fallback_t &o HB_UNUSED) = default;
hb_iter_with_fallback_t& operator = (hb_iter_with_fallback_t &&o HB_UNUSED) = default;
};
/*
* Meta-programming predicates.
*/
/* hb_is_iterator() / hb_is_iterator_of() */
template<typename Iter, typename Item>
struct hb_is_iterator_of
{
template <typename Item2 = Item>
static hb_true_type impl (hb_priority<2>, hb_iter_t<Iter, hb_type_identity<Item2>> *);
static hb_false_type impl (hb_priority<0>, const void *);
public:
static constexpr bool value = decltype (impl (hb_prioritize, hb_declval (Iter*)))::value;
};
#define hb_is_iterator_of(Iter, Item) hb_is_iterator_of<Iter, Item>::value
#define hb_is_iterator(Iter) hb_is_iterator_of (Iter, typename Iter::item_t)
#define hb_is_sorted_iterator_of(Iter, Item) (hb_is_iterator_of<Iter, Item>::value && Iter::is_sorted_iterator)
#define hb_is_sorted_iterator(Iter) hb_is_sorted_iterator_of (Iter, typename Iter::item_t)
/* hb_is_iterable() */
template <typename T>
struct hb_is_iterable
{
private:
template <typename U>
static auto impl (hb_priority<1>) -> decltype (hb_declval (U).iter (), hb_true_type ());
template <typename>
static hb_false_type impl (hb_priority<0>);
public:
static constexpr bool value = decltype (impl<T> (hb_prioritize))::value;
};
#define hb_is_iterable(Iterable) hb_is_iterable<Iterable>::value
/* hb_is_source_of() / hb_is_sink_of() */
template<typename Iter, typename Item>
struct hb_is_source_of
{
private:
template <typename Iter2 = Iter,
hb_enable_if (hb_is_convertible (typename Iter2::item_t, hb_add_lvalue_reference<const Item>))>
static hb_true_type impl (hb_priority<2>);
template <typename Iter2 = Iter>
static auto impl (hb_priority<1>) -> decltype (hb_declval (Iter2) >> hb_declval (Item &), hb_true_type ());
static hb_false_type impl (hb_priority<0>);
public:
static constexpr bool value = decltype (impl (hb_prioritize))::value;
};
#define hb_is_source_of(Iter, Item) hb_is_source_of<Iter, Item>::value
template<typename Iter, typename Item>
struct hb_is_sink_of
{
private:
template <typename Iter2 = Iter,
hb_enable_if (hb_is_convertible (typename Iter2::item_t, hb_add_lvalue_reference<Item>))>
static hb_true_type impl (hb_priority<2>);
template <typename Iter2 = Iter>
static auto impl (hb_priority<1>) -> decltype (hb_declval (Iter2) << hb_declval (Item), hb_true_type ());
static hb_false_type impl (hb_priority<0>);
public:
static constexpr bool value = decltype (impl (hb_prioritize))::value;
};
#define hb_is_sink_of(Iter, Item) hb_is_sink_of<Iter, Item>::value
/* This is commonly used, so define: */
#define hb_is_sorted_source_of(Iter, Item) \
(hb_is_source_of(Iter, Item) && Iter::is_sorted_iterator)
struct
{
template <typename Iterable,
hb_requires (hb_is_iterable (Iterable))>
unsigned operator () (const Iterable &_) const { return hb_len (hb_iter (_)); }
unsigned operator () (unsigned _) const { return _; }
}
HB_FUNCOBJ (hb_len_of);
/* Range-based 'for' for iterables. */
template <typename Iterable,
hb_requires (hb_is_iterable (Iterable))>
static inline auto begin (Iterable&& iterable) HB_AUTO_RETURN (hb_iter (iterable).begin ())
template <typename Iterable,
hb_requires (hb_is_iterable (Iterable))>
static inline auto end (Iterable&& iterable) HB_AUTO_RETURN (hb_iter (iterable).end ())
/* begin()/end() are NOT looked up non-ADL. So each namespace must declare them.
* Do it for namespace OT. */
namespace OT {
template <typename Iterable,
hb_requires (hb_is_iterable (Iterable))>
static inline auto begin (Iterable&& iterable) HB_AUTO_RETURN (hb_iter (iterable).begin ())
template <typename Iterable,
hb_requires (hb_is_iterable (Iterable))>
static inline auto end (Iterable&& iterable) HB_AUTO_RETURN (hb_iter (iterable).end ())
}
/*
* Adaptors, combiners, etc.
*/
template <typename Lhs, typename Rhs,
hb_requires (hb_is_iterator (Lhs))>
static inline auto
operator | (Lhs&& lhs, Rhs&& rhs) HB_AUTO_RETURN (std::forward<Rhs> (rhs) (std::forward<Lhs> (lhs)))
/* hb_map(), hb_filter(), hb_reduce() */
enum class hb_function_sortedness_t {
NOT_SORTED,
RETAINS_SORTING,
SORTED,
};
template <typename Iter, typename Proj, hb_function_sortedness_t Sorted,
hb_requires (hb_is_iterator (Iter))>
struct hb_map_iter_t :
hb_iter_t<hb_map_iter_t<Iter, Proj, Sorted>,
decltype (hb_get (hb_declval (Proj), *hb_declval (Iter)))>
{
hb_map_iter_t (const Iter& it, Proj f_) : it (it), f (f_) {}
typedef decltype (hb_get (hb_declval (Proj), *hb_declval (Iter))) __item_t__;
static constexpr bool is_random_access_iterator = Iter::is_random_access_iterator;
static constexpr bool is_sorted_iterator =
Sorted == hb_function_sortedness_t::SORTED ? true :
Sorted == hb_function_sortedness_t::RETAINS_SORTING ? Iter::is_sorted_iterator :
false;
__item_t__ __item__ () const { return hb_get (f.get (), *it); }
__item_t__ __item_at__ (unsigned i) const { return hb_get (f.get (), it[i]); }
bool __more__ () const { return bool (it); }
unsigned __len__ () const { return it.len (); }
void __next__ () { ++it; }
void __forward__ (unsigned n) { it += n; }
void __prev__ () { --it; }
void __rewind__ (unsigned n) { it -= n; }
hb_map_iter_t __end__ () const { return hb_map_iter_t (it._end (), f); }
bool operator != (const hb_map_iter_t& o) const
{ return it != o.it; }
private:
Iter it;
mutable hb_reference_wrapper<Proj> f;
};
template <typename Proj, hb_function_sortedness_t Sorted>
struct hb_map_iter_factory_t
{
hb_map_iter_factory_t (Proj f) : f (f) {}
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
hb_map_iter_t<Iter, Proj, Sorted>
operator () (Iter it)
{ return hb_map_iter_t<Iter, Proj, Sorted> (it, f); }
private:
Proj f;
};
struct
{
template <typename Proj>
hb_map_iter_factory_t<Proj, hb_function_sortedness_t::NOT_SORTED>
operator () (Proj&& f) const
{ return hb_map_iter_factory_t<Proj, hb_function_sortedness_t::NOT_SORTED> (f); }
}
HB_FUNCOBJ (hb_map);
struct
{
template <typename Proj>
hb_map_iter_factory_t<Proj, hb_function_sortedness_t::RETAINS_SORTING>
operator () (Proj&& f) const
{ return hb_map_iter_factory_t<Proj, hb_function_sortedness_t::RETAINS_SORTING> (f); }
}
HB_FUNCOBJ (hb_map_retains_sorting);
struct
{
template <typename Proj>
hb_map_iter_factory_t<Proj, hb_function_sortedness_t::SORTED>
operator () (Proj&& f) const
{ return hb_map_iter_factory_t<Proj, hb_function_sortedness_t::SORTED> (f); }
}
HB_FUNCOBJ (hb_map_sorted);
template <typename Iter, typename Pred, typename Proj,
hb_requires (hb_is_iterator (Iter))>
struct hb_filter_iter_t :
hb_iter_with_fallback_t<hb_filter_iter_t<Iter, Pred, Proj>,
typename Iter::item_t>
{
hb_filter_iter_t (const Iter& it_, Pred p_, Proj f_) : it (it_), p (p_), f (f_)
{ while (it && !hb_has (p.get (), hb_get (f.get (), *it))) ++it; }
typedef typename Iter::item_t __item_t__;
static constexpr bool is_sorted_iterator = Iter::is_sorted_iterator;
__item_t__ __item__ () const { return *it; }
bool __more__ () const { return bool (it); }
void __next__ () { do ++it; while (it && !hb_has (p.get (), hb_get (f.get (), *it))); }
void __prev__ () { do --it; while (it && !hb_has (p.get (), hb_get (f.get (), *it))); }
hb_filter_iter_t __end__ () const { return hb_filter_iter_t (it._end (), p, f); }
bool operator != (const hb_filter_iter_t& o) const
{ return it != o.it; }
private:
Iter it;
mutable hb_reference_wrapper<Pred> p;
mutable hb_reference_wrapper<Proj> f;
};
template <typename Pred, typename Proj>
struct hb_filter_iter_factory_t
{
hb_filter_iter_factory_t (Pred p, Proj f) : p (p), f (f) {}
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
hb_filter_iter_t<Iter, Pred, Proj>
operator () (Iter it)
{ return hb_filter_iter_t<Iter, Pred, Proj> (it, p, f); }
private:
Pred p;
Proj f;
};
struct
{
template <typename Pred = decltype ((hb_identity)),
typename Proj = decltype ((hb_identity))>
hb_filter_iter_factory_t<Pred, Proj>
operator () (Pred&& p = hb_identity, Proj&& f = hb_identity) const
{ return hb_filter_iter_factory_t<Pred, Proj> (p, f); }
}
HB_FUNCOBJ (hb_filter);
template <typename Redu, typename InitT>
struct hb_reduce_t
{
hb_reduce_t (Redu r, InitT init_value) : r (r), init_value (init_value) {}
template <typename Iter,
hb_requires (hb_is_iterator (Iter)),
typename AccuT = hb_decay<decltype (hb_declval (Redu) (hb_declval (InitT), hb_declval (typename Iter::item_t)))>>
AccuT
operator () (Iter it)
{
AccuT value = init_value;
for (; it; ++it)
value = r (value, *it);
return value;
}
private:
Redu r;
InitT init_value;
};
struct
{
template <typename Redu, typename InitT>
hb_reduce_t<Redu, InitT>
operator () (Redu&& r, InitT init_value) const
{ return hb_reduce_t<Redu, InitT> (r, init_value); }
}
HB_FUNCOBJ (hb_reduce);
/* hb_zip() */
template <typename A, typename B>
struct hb_zip_iter_t :
hb_iter_t<hb_zip_iter_t<A, B>,
hb_pair_t<typename A::item_t, typename B::item_t>>
{
hb_zip_iter_t () {}
hb_zip_iter_t (const A& a, const B& b) : a (a), b (b) {}
typedef hb_pair_t<typename A::item_t, typename B::item_t> __item_t__;
static constexpr bool is_random_access_iterator =
A::is_random_access_iterator &&
B::is_random_access_iterator;
/* Note. The following categorization is only valid if A is strictly sorted,
* ie. does NOT have duplicates. Previously I tried to categorize sortedness
* more granularly, see commits:
*
* 513762849a683914fc266a17ddf38f133cccf072
* 4d3cf2adb669c345cc43832d11689271995e160a
*
* However, that was not enough, since hb_sorted_array_t, hb_sorted_vector_t,
* SortedArrayOf, etc all needed to be updated to add more variants. At that
* point I saw it not worth the effort, and instead we now deem all sorted
* collections as essentially strictly-sorted for the purposes of zip.
*
* The above assumption is not as bad as it sounds. Our "sorted" comes with
* no guarantees. It's just a contract, put in place to help you remember,
* and think about, whether an iterator you receive is expected to be
* sorted or not. As such, it's not perfect by definition, and should not
* be treated so. The inaccuracy here just errs in the direction of being
* more permissive, so your code compiles instead of erring on the side of
* marking your zipped iterator unsorted in which case your code won't
* compile.
*
* This semantical limitation does NOT affect logic in any other place I
* know of as of this writing.
*/
static constexpr bool is_sorted_iterator = A::is_sorted_iterator;
__item_t__ __item__ () const { return __item_t__ (*a, *b); }
__item_t__ __item_at__ (unsigned i) const { return __item_t__ (a[i], b[i]); }
bool __more__ () const { return bool (a) && bool (b); }
unsigned __len__ () const { return hb_min (a.len (), b.len ()); }
void __next__ () { ++a; ++b; }
void __forward__ (unsigned n) { a += n; b += n; }
void __prev__ () { --a; --b; }
void __rewind__ (unsigned n) { a -= n; b -= n; }
hb_zip_iter_t __end__ () const { return hb_zip_iter_t (a._end (), b._end ()); }
/* Note, we should stop if ANY of the iters reaches end. As such two compare
* unequal if both items are unequal, NOT if either is unequal. */
bool operator != (const hb_zip_iter_t& o) const
{ return a != o.a && b != o.b; }
private:
A a;
B b;
};
struct
{ HB_PARTIALIZE(2);
template <typename A, typename B,
hb_requires (hb_is_iterable (A) && hb_is_iterable (B))>
hb_zip_iter_t<hb_iter_type<A>, hb_iter_type<B>>
operator () (A&& a, B&& b) const
{ return hb_zip_iter_t<hb_iter_type<A>, hb_iter_type<B>> (hb_iter (a), hb_iter (b)); }
}
HB_FUNCOBJ (hb_zip);
/* hb_concat() */
template <typename A, typename B>
struct hb_concat_iter_t :
hb_iter_t<hb_concat_iter_t<A, B>, typename A::item_t>
{
hb_concat_iter_t () {}
hb_concat_iter_t (A& a, B& b) : a (a), b (b) {}
hb_concat_iter_t (const A& a, const B& b) : a (a), b (b) {}
typedef typename A::item_t __item_t__;
static constexpr bool is_random_access_iterator =
A::is_random_access_iterator &&
B::is_random_access_iterator;
static constexpr bool is_sorted_iterator = false;
__item_t__ __item__ () const
{
if (!a)
return *b;
return *a;
}
__item_t__ __item_at__ (unsigned i) const
{
unsigned a_len = a.len ();
if (i < a_len)
return a[i];
return b[i - a_len];
}
bool __more__ () const { return bool (a) || bool (b); }
unsigned __len__ () const { return a.len () + b.len (); }
void __next__ ()
{
if (a)
++a;
else
++b;
}
void __forward__ (unsigned n)
{
if (!n) return;
if (!is_random_access_iterator) {
while (n-- && *this) {
(*this)++;
}
return;
}
unsigned a_len = a.len ();
if (n > a_len) {
n -= a_len;
a.__forward__ (a_len);
b.__forward__ (n);
} else {
a.__forward__ (n);
}
}
hb_concat_iter_t __end__ () const { return hb_concat_iter_t (a._end (), b._end ()); }
bool operator != (const hb_concat_iter_t& o) const
{
return a != o.a
|| b != o.b;
}
private:
A a;
B b;
};
struct
{ HB_PARTIALIZE(2);
template <typename A, typename B,
hb_requires (hb_is_iterable (A) && hb_is_iterable (B))>
hb_concat_iter_t<hb_iter_type<A>, hb_iter_type<B>>
operator () (A&& a, B&& b) const
{ return hb_concat_iter_t<hb_iter_type<A>, hb_iter_type<B>> (hb_iter (a), hb_iter (b)); }
}
HB_FUNCOBJ (hb_concat);
/* hb_apply() */
template <typename Appl>
struct hb_apply_t
{
hb_apply_t (Appl a) : a (a) {}
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
void operator () (Iter it)
{
for (; it; ++it)
(void) hb_invoke (a, *it);
}
private:
Appl a;
};
struct
{
template <typename Appl> hb_apply_t<Appl>
operator () (Appl&& a) const
{ return hb_apply_t<Appl> (a); }
template <typename Appl> hb_apply_t<Appl&>
operator () (Appl *a) const
{ return hb_apply_t<Appl&> (*a); }
}
HB_FUNCOBJ (hb_apply);
/* hb_range()/hb_iota()/hb_repeat() */
template <typename T, typename S>
struct hb_range_iter_t :
hb_iter_t<hb_range_iter_t<T, S>, T>
{
hb_range_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 hb_ridentity (v); }
__item_t__ __item_at__ (unsigned j) const { return v + j * step; }
bool __more__ () const { return v != end_; }
unsigned __len__ () const { return !step ? UINT_MAX : (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_range_iter_t __end__ () const { return hb_range_iter_t (end_, end_, step); }
bool operator != (const hb_range_iter_t& o) const
{ return v != o.v; }
private:
static inline T end_for (T start, T end_, S step)
{
if (!step)
return end_;
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_range_iter_t<T, unsigned>
operator () (T end = (unsigned) -1) const
{ return hb_range_iter_t<T, unsigned> (0, end, 1u); }
template <typename T, typename S = unsigned> hb_range_iter_t<T, S>
operator () (T start, T end, S step = 1u) const
{ return hb_range_iter_t<T, S> (start, end, step); }
}
HB_FUNCOBJ (hb_range);
template <typename T, typename S>
struct hb_iota_iter_t :
hb_iter_with_fallback_t<hb_iota_iter_t<T, S>, T>
{
hb_iota_iter_t (T start, S step) : v (start), step (step) {}
private:
template <typename S2 = S>
auto
inc (hb_type_identity<S2> s, hb_priority<1>)
-> hb_void_t<decltype (hb_invoke (std::forward<hb_type_identity<S2>> (s),
hb_declval<T&> ()))>
{ v = hb_invoke (std::forward<hb_type_identity<S2>> (s), v); }
void
inc (S s, hb_priority<0>)
{ v += s; }
public:
typedef T __item_t__;
static constexpr bool is_random_access_iterator = true;
static constexpr bool is_sorted_iterator = true;
__item_t__ __item__ () const { return hb_ridentity (v); }
bool __more__ () const { return true; }
unsigned __len__ () const { return UINT_MAX; }
void __next__ () { inc (step, hb_prioritize); }
void __prev__ () { v -= step; }
hb_iota_iter_t __end__ () const { return *this; }
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_iota_iter_t<T, S>
operator () (T start = 0u, S step = 1u) const
{ return hb_iota_iter_t<T, S> (start, step); }
}
HB_FUNCOBJ (hb_iota);
template <typename T>
struct hb_repeat_iter_t :
hb_iter_t<hb_repeat_iter_t<T>, T>
{
hb_repeat_iter_t (T value) : v (value) {}
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; }
bool __more__ () const { return true; }
unsigned __len__ () const { return UINT_MAX; }
void __next__ () {}
void __forward__ (unsigned) {}
void __prev__ () {}
void __rewind__ (unsigned) {}
hb_repeat_iter_t __end__ () const { return *this; }
bool operator != (const hb_repeat_iter_t& o) const { return true; }
private:
T v;
};
struct
{
template <typename T> hb_repeat_iter_t<T>
operator () (T value) const
{ return hb_repeat_iter_t<T> (value); }
}
HB_FUNCOBJ (hb_repeat);
/* hb_enumerate()/hb_take() */
struct
{
template <typename Iterable,
typename Index = unsigned,
hb_requires (hb_is_iterable (Iterable))>
auto operator () (Iterable&& it, Index start = 0u) const HB_AUTO_RETURN
( hb_zip (hb_iota (start), it) )
}
HB_FUNCOBJ (hb_enumerate);
struct
{ HB_PARTIALIZE(2);
template <typename Iterable,
hb_requires (hb_is_iterable (Iterable))>
auto operator () (Iterable&& it, unsigned count) const HB_AUTO_RETURN
( hb_zip (hb_range (count), it) | hb_map_retains_sorting (hb_second) )
/* Specialization arrays. */
template <typename Type> inline hb_array_t<Type>
operator () (hb_array_t<Type> array, unsigned count) const
{ return array.sub_array (0, count); }
template <typename Type> inline hb_sorted_array_t<Type>
operator () (hb_sorted_array_t<Type> array, unsigned count) const
{ return array.sub_array (0, count); }
}
HB_FUNCOBJ (hb_take);
struct
{ HB_PARTIALIZE(2);
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
auto operator () (Iter it, unsigned count) const HB_AUTO_RETURN
(
+ hb_iota (it, hb_add (count))
| hb_map (hb_take (count))
| hb_take ((hb_len (it) + count - 1) / count)
)
}
HB_FUNCOBJ (hb_chop);
/* hb_sink() */
template <typename Sink>
struct hb_sink_t
{
hb_sink_t (Sink s) : s (s) {}
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
void operator () (Iter it)
{
for (; it; ++it)
s << *it;
}
private:
Sink s;
};
struct
{
template <typename Sink> hb_sink_t<Sink>
operator () (Sink&& s) const
{ return hb_sink_t<Sink> (s); }
template <typename Sink> hb_sink_t<Sink&>
operator () (Sink *s) const
{ return hb_sink_t<Sink&> (*s); }
}
HB_FUNCOBJ (hb_sink);
/* hb-drain: hb_sink to void / blackhole / /dev/null. */
struct
{
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
void operator () (Iter it) const
{
for (; it; ++it)
(void) *it;
}
}
HB_FUNCOBJ (hb_drain);
/* hb_unzip(): unzip and sink to two sinks. */
template <typename Sink1, typename Sink2>
struct hb_unzip_t
{
hb_unzip_t (Sink1 s1, Sink2 s2) : s1 (s1), s2 (s2) {}
template <typename Iter,
hb_requires (hb_is_iterator (Iter))>
void operator () (Iter it)
{
for (; it; ++it)
{
const auto &v = *it;
s1 << v.first;
s2 << v.second;
}
}
private:
Sink1 s1;
Sink2 s2;
};
struct
{
template <typename Sink1, typename Sink2> hb_unzip_t<Sink1, Sink2>
operator () (Sink1&& s1, Sink2&& s2) const
{ return hb_unzip_t<Sink1, Sink2> (s1, s2); }
template <typename Sink1, typename Sink2> hb_unzip_t<Sink1&, Sink2&>
operator () (Sink1 *s1, Sink2 *s2) const
{ return hb_unzip_t<Sink1&, Sink2&> (*s1, *s2); }
}
HB_FUNCOBJ (hb_unzip);
/* hb-all, hb-any, hb-none. */
struct
{
template <typename Iterable,
typename Pred = decltype ((hb_identity)),
typename Proj = decltype ((hb_identity)),
hb_requires (hb_is_iterable (Iterable))>
bool operator () (Iterable&& c,
Pred&& p = hb_identity,
Proj&& f = hb_identity) const
{
for (auto it = hb_iter (c); it; ++it)
if (!hb_match (p, hb_get (f, *it)))
return false;
return true;
}
}
HB_FUNCOBJ (hb_all);
struct
{
template <typename Iterable,
typename Pred = decltype ((hb_identity)),
typename Proj = decltype ((hb_identity)),
hb_requires (hb_is_iterable (Iterable))>
bool operator () (Iterable&& c,
Pred&& p = hb_identity,
Proj&& f = hb_identity) const
{
for (auto it = hb_iter (c); it; ++it)
if (hb_match (p, hb_get (f, *it)))
return true;
return false;
}
}
HB_FUNCOBJ (hb_any);
struct
{
template <typename Iterable,
typename Pred = decltype ((hb_identity)),
typename Proj = decltype ((hb_identity)),
hb_requires (hb_is_iterable (Iterable))>
bool operator () (Iterable&& c,
Pred&& p = hb_identity,
Proj&& f = hb_identity) const
{
for (auto it = hb_iter (c); it; ++it)
if (hb_match (p, hb_get (f, *it)))
return false;
return true;
}
}
HB_FUNCOBJ (hb_none);
/*
* Algorithms operating on iterators.
*/
template <typename C, typename V,
hb_requires (hb_is_iterable (C))>
inline void
hb_fill (C&& c, const V &v)
{
for (auto i = hb_iter (c); i; i++)
*i = v;
}
template <typename S, typename D>
inline void
hb_copy (S&& is, D&& id)
{
hb_iter (is) | hb_sink (id);
}
#endif /* HB_ITER_HH */