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GeezerVison is showing github.com — circular_buffer/include/boost/circular_buffer/base.hpp at develop · boostorg/circular_buffer Expand file tree/ Copy pathbase.hppMore file actions 3134 lines (2928 loc) · 150 KB / Copy pathbase.hppFile metadata and controls3134 lines (2928 loc) · 150 KB 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 // Implementation of the base circular buffer. // Copyright (c) 2003-2008 Jan Gaspar // Copyright (c) 2013 Paul A. Bristow // Doxygen comments changed. // Copyright (c) 2013 Antony Polukhin // Move semantics implementation. // Copyright 2014,2018 Glen Joseph Fernandes // ([email protected]) // Use, modification, and distribution is subject to the Boost Software // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #if !defined(BOOST_CIRCULAR_BUFFER_BASE_HPP) #define BOOST_CIRCULAR_BUFFER_BASE_HPP #if defined(_MSC_VER) #pragma once #endif #include <boost/config.hpp> #include <boost/concept_check.hpp> #include <boost/limits.hpp> #include <boost/core/allocator_access.hpp> #include <boost/core/empty_value.hpp> #include <boost/type_traits/is_stateless.hpp> #include <boost/type_traits/is_integral.hpp> #include <boost/type_traits/is_scalar.hpp> #include <boost/type_traits/is_nothrow_move_constructible.hpp> #include <boost/type_traits/is_nothrow_move_assignable.hpp> #include <boost/type_traits/is_copy_constructible.hpp> #include <boost/type_traits/conditional.hpp> #include <boost/move/adl_move_swap.hpp> #include <boost/move/move.hpp> #include <algorithm> #include <iterator> #include <utility> #include <deque> #include <stdexcept> #if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3205)) #include <stddef.h> #endif namespace boost { /*! \class circular_buffer \brief Circular buffer - a STL compliant container. \tparam T The type of the elements stored in the <code>circular_buffer</code>. \par Type Requirements T The <code>T</code> has to be <a href="https://www.boost.org/sgi/stl/Assignable.html"> SGIAssignable</a> (SGI STL defined combination of <a href="../../../utility/Assignable.html"> Assignable</a> and <a href="../../../utility/CopyConstructible.html">CopyConstructible</a>). Moreover <code>T</code> has to be <a href="https://www.boost.org/sgi/stl/DefaultConstructible.html"> DefaultConstructible</a> if supplied as a default parameter when invoking some of the <code>circular_buffer</code>'s methods e.g. <code>insert(iterator pos, const value_type& item = %value_type())</code>. And <a href="https://www.boost.org/sgi/stl/EqualityComparable.html">EqualityComparable</a> and/or <a href="../../../utility/LessThanComparable.html">LessThanComparable</a> if the <code>circular_buffer</code> will be compared with another container. \tparam Alloc The allocator type used for all internal memory management. \par Type Requirements Alloc The <code>Alloc</code> has to meet the allocator requirements imposed by STL. \par Default Alloc std::allocator<T> For detailed documentation of the circular_buffer visit: http://www.boost.org/libs/circular_buffer/doc/circular_buffer.html */ template <class T, class Alloc> class circular_buffer : /*! \cond */ #if BOOST_CB_ENABLE_DEBUG public cb_details::debug_iterator_registry, #endif /*! \endcond */ private empty_value<Alloc> { typedef empty_value<Alloc> base; // Requirements //BOOST_CLASS_REQUIRE(T, boost, SGIAssignableConcept); //BOOST_CONCEPT_ASSERT((Assignable<T>)); //BOOST_CONCEPT_ASSERT((CopyConstructible<T>)); //BOOST_CONCEPT_ASSERT((DefaultConstructible<T>)); // Required if the circular_buffer will be compared with anther container. //BOOST_CONCEPT_ASSERT((EqualityComparable<T>)); //BOOST_CONCEPT_ASSERT((LessThanComparable<T>)); public: // Basic types //! The type of this <code>circular_buffer</code>. typedef circular_buffer<T, Alloc> this_type; //! The type of elements stored in the <code>circular_buffer</code>. typedef typename Alloc::value_type value_type; //! A pointer to an element. typedef typename allocator_pointer<Alloc>::type pointer; //! A const pointer to the element. typedef typename allocator_const_pointer<Alloc>::type const_pointer; //! A reference to an element. typedef value_type& reference; //! A const reference to an element. typedef const value_type& const_reference; //! The distance type. /*! (A signed integral type used to represent the distance between two iterators.) */ typedef typename allocator_difference_type<Alloc>::type difference_type; //! The size type. /*! (An unsigned integral type that can represent any non-negative value of the container's distance type.) */ typedef typename allocator_size_type<Alloc>::type size_type; //! The type of an allocator used in the <code>circular_buffer</code>. typedef Alloc allocator_type; // Iterators //! A const (random access) iterator used to iterate through the <code>circular_buffer</code>. typedef cb_details::iterator< circular_buffer<T, Alloc>, cb_details::const_traits<Alloc> > const_iterator; //! A (random access) iterator used to iterate through the <code>circular_buffer</code>. typedef cb_details::iterator< circular_buffer<T, Alloc>, cb_details::nonconst_traits<Alloc> > iterator; //! A const iterator used to iterate backwards through a <code>circular_buffer</code>. typedef std::reverse_iterator<const_iterator> const_reverse_iterator; //! An iterator used to iterate backwards through a <code>circular_buffer</code>. typedef std::reverse_iterator<iterator> reverse_iterator; // Container specific types //! An array range. /*! (A typedef for the <a href="https://www.boost.org/sgi/stl/pair.html"><code>std::pair</code></a> where its first element is a pointer to a beginning of an array and its second element represents a size of the array.) */ typedef std::pair<pointer, size_type> array_range; //! A range of a const array. /*! (A typedef for the <a href="https://www.boost.org/sgi/stl/pair.html"><code>std::pair</code></a> where its first element is a pointer to a beginning of a const array and its second element represents a size of the const array.) */ typedef std::pair<const_pointer, size_type> const_array_range; //! The capacity type. /*! (Same as <code>size_type</code> - defined for consistency with the __cbso class. */ // <a href="space_optimized.html"><code>circular_buffer_space_optimized</code></a>.) typedef size_type capacity_type; // Helper types //! A type representing the "best" way to pass the value_type to a method. typedef const value_type& param_value_type; //! A type representing rvalue from param type. //! On compilers without rvalue references support this type is the Boost.Moves type used for emulation. typedef BOOST_RV_REF(value_type) rvalue_type; private: // Member variables //! The internal buffer used for storing elements in the circular buffer. pointer m_buff; //! The internal buffer's end (end of the storage space). pointer m_end; //! The virtual beginning of the circular buffer. pointer m_first; //! The virtual end of the circular buffer (one behind the last element). pointer m_last; //! The number of items currently stored in the circular buffer. size_type m_size; // Friends #if defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) friend iterator; friend const_iterator; #else template <class Buff, class Traits> friend struct cb_details::iterator; #endif public: // Allocator //! Get the allocator. /*! \return The allocator. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>get_allocator()</code> for obtaining an allocator %reference. */ allocator_type get_allocator() const BOOST_NOEXCEPT { return alloc(); } //! Get the allocator reference. /*! \return A reference to the allocator. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \note This method was added in order to optimize obtaining of the allocator with a state, although use of stateful allocators in STL is discouraged. \sa <code>get_allocator() const</code> */ allocator_type& get_allocator() BOOST_NOEXCEPT { return alloc(); } // Element access //! Get the iterator pointing to the beginning of the <code>circular_buffer</code>. /*! \return A random access iterator pointing to the first element of the <code>circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>end()</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>end()</code>, <code>rbegin()</code>, <code>rend()</code> */ iterator begin() BOOST_NOEXCEPT { return iterator(this, empty() ? 0 : m_first); } //! Get the iterator pointing to the end of the <code>circular_buffer</code>. /*! \return A random access iterator pointing to the element "one behind" the last element of the <code> circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>begin()</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>begin()</code>, <code>rbegin()</code>, <code>rend()</code> */ iterator end() BOOST_NOEXCEPT { return iterator(this, 0); } //! Get the const iterator pointing to the beginning of the <code>circular_buffer</code>. /*! \return A const random access iterator pointing to the first element of the <code>circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>end() const</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>end() const</code>, <code>rbegin() const</code>, <code>rend() const</code> */ const_iterator begin() const BOOST_NOEXCEPT { return const_iterator(this, empty() ? 0 : m_first); } const_iterator cbegin() const BOOST_NOEXCEPT { return begin(); } //! Get the const iterator pointing to the end of the <code>circular_buffer</code>. /*! \return A const random access iterator pointing to the element "one behind" the last element of the <code> circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>begin() const</code> const. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>begin() const</code>, <code>rbegin() const</code>, <code>rend() const</code> */ const_iterator end() const BOOST_NOEXCEPT { return const_iterator(this, 0); } const_iterator cend() const BOOST_NOEXCEPT { return end(); } //! Get the iterator pointing to the beginning of the "reversed" <code>circular_buffer</code>. /*! \return A reverse random access iterator pointing to the last element of the <code>circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>rend()</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>rend()</code>, <code>begin()</code>, <code>end()</code> */ reverse_iterator rbegin() BOOST_NOEXCEPT { return reverse_iterator(end()); } //! Get the iterator pointing to the end of the "reversed" <code>circular_buffer</code>. /*! \return A reverse random access iterator pointing to the element "one before" the first element of the <code> circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>rbegin()</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>rbegin()</code>, <code>begin()</code>, <code>end()</code> */ reverse_iterator rend() BOOST_NOEXCEPT { return reverse_iterator(begin()); } //! Get the const iterator pointing to the beginning of the "reversed" <code>circular_buffer</code>. /*! \return A const reverse random access iterator pointing to the last element of the <code>circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>rend() const</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>rend() const</code>, <code>begin() const</code>, <code>end() const</code> */ const_reverse_iterator rbegin() const BOOST_NOEXCEPT { return const_reverse_iterator(end()); } //! Get the const iterator pointing to the end of the "reversed" <code>circular_buffer</code>. /*! \return A const reverse random access iterator pointing to the element "one before" the first element of the <code>circular_buffer</code>. If the <code>circular_buffer</code> is empty it returns an iterator equal to the one returned by <code>rbegin() const</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>rbegin() const</code>, <code>begin() const</code>, <code>end() const</code> */ const_reverse_iterator rend() const BOOST_NOEXCEPT { return const_reverse_iterator(begin()); } //! Get the element at the <code>index</code> position. /*! \pre <code>0 \<= index \&\& index \< size()</code> \param index The position of the element. \return A reference to the element at the <code>index</code> position. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>at()</code> */ reference operator [] (size_type index) { BOOST_CB_ASSERT(index < size()); // check for invalid index return *add(m_first, index); } //! Get the element at the <code>index</code> position. /*! \pre <code>0 \<= index \&\& index \< size()</code> \param index The position of the element. \return A const reference to the element at the <code>index</code> position. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>\link at(size_type)const at() const \endlink</code> */ const_reference operator [] (size_type index) const { BOOST_CB_ASSERT(index < size()); // check for invalid index return *add(m_first, index); } //! Get the element at the <code>index</code> position. /*! \param index The position of the element. \return A reference to the element at the <code>index</code> position. \throws <code>std::out_of_range</code> when the <code>index</code> is invalid (when <code>index >= size()</code>). \par Exception Safety Strong. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>\link operator[](size_type) operator[] \endlink</code> */ reference at(size_type index) { check_position(index); return (*this)[index]; } //! Get the element at the <code>index</code> position. /*! \param index The position of the element. \return A const reference to the element at the <code>index</code> position. \throws <code>std::out_of_range</code> when the <code>index</code> is invalid (when <code>index >= size()</code>). \par Exception Safety Strong. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>\link operator[](size_type)const operator[] const \endlink</code> */ const_reference at(size_type index) const { check_position(index); return (*this)[index]; } //! Get the first element. /*! \pre <code>!empty()</code> \return A reference to the first element of the <code>circular_buffer</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>back()</code> */ reference front() { BOOST_CB_ASSERT(!empty()); // check for empty buffer (front element not available) return *m_first; } //! Get the last element. /*! \pre <code>!empty()</code> \return A reference to the last element of the <code>circular_buffer</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>front()</code> */ reference back() { BOOST_CB_ASSERT(!empty()); // check for empty buffer (back element not available) return *((m_last == m_buff ? m_end : m_last) - 1); } //! Get the first element. /*! \pre <code>!empty()</code> \return A const reference to the first element of the <code>circular_buffer</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>back() const</code> */ const_reference front() const { BOOST_CB_ASSERT(!empty()); // check for empty buffer (front element not available) return *m_first; } //! Get the last element. /*! \pre <code>!empty()</code> \return A const reference to the last element of the <code>circular_buffer</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>front() const</code> */ const_reference back() const { BOOST_CB_ASSERT(!empty()); // check for empty buffer (back element not available) return *((m_last == m_buff ? m_end : m_last) - 1); } //! Get the first continuous array of the internal buffer. /*! This method in combination with <code>array_two()</code> can be useful when passing the stored data into a legacy C API as an array. Suppose there is a <code>circular_buffer</code> of capacity 10, containing 7 characters <code>'a', 'b', ..., 'g'</code> where <code>buff[0] == 'a'</code>, <code>buff[1] == 'b'</code>, ... and <code>buff[6] == 'g'</code>:<br><br> <code>circular_buffer<char> buff(10);</code><br><br> The internal representation is often not linear and the state of the internal buffer may look like this:<br> <br><code> |e|f|g| | | |a|b|c|d|<br> end ___^<br> begin _______^</code><br><br> where <code>|a|b|c|d|</code> represents the "array one", <code>|e|f|g|</code> represents the "array two" and <code>| | | |</code> is a free space.<br> Now consider a typical C style function for writing data into a file:<br><br> <code>int write(int file_desc, char* buff, int num_bytes);</code><br><br> There are two ways how to write the content of the <code>circular_buffer</code> into a file. Either relying on <code>array_one()</code> and <code>array_two()</code> methods and calling the write function twice:<br><br> <code>array_range ar = buff.array_one();<br> write(file_desc, ar.first, ar.second);<br> ar = buff.array_two();<br> write(file_desc, ar.first, ar.second);</code><br><br> Or relying on the <code>linearize()</code> method:<br><br><code> write(file_desc, buff.linearize(), buff.size());</code><br><br> Since the complexity of <code>array_one()</code> and <code>array_two()</code> methods is constant the first option is suitable when calling the write method is "cheap". On the other hand the second option is more suitable when calling the write method is more "expensive" than calling the <code>linearize()</code> method whose complexity is linear. \return The array range of the first continuous array of the internal buffer. In the case the <code>circular_buffer</code> is empty the size of the returned array is <code>0</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \warning In general invoking any method which modifies the internal state of the circular_buffer may delinearize the internal buffer and invalidate the array ranges returned by <code>array_one()</code> and <code>array_two()</code> (and their const versions). \note In the case the internal buffer is linear e.g. <code>|a|b|c|d|e|f|g| | | |</code> the "array one" is represented by <code>|a|b|c|d|e|f|g|</code> and the "array two" does not exist (the <code>array_two()</code> method returns an array with the size <code>0</code>). \sa <code>array_two()</code>, <code>linearize()</code> */ array_range array_one() { return array_range(m_first, (m_last <= m_first && !empty() ? m_end : m_last) - m_first); } //! Get the second continuous array of the internal buffer. /*! This method in combination with <code>array_one()</code> can be useful when passing the stored data into a legacy C API as an array. \return The array range of the second continuous array of the internal buffer. In the case the internal buffer is linear or the <code>circular_buffer</code> is empty the size of the returned array is <code>0</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>array_one()</code> */ array_range array_two() { return array_range(m_buff, m_last <= m_first && !empty() ? m_last - m_buff : 0); } //! Get the first continuous array of the internal buffer. /*! This method in combination with <code>array_two() const</code> can be useful when passing the stored data into a legacy C API as an array. \return The array range of the first continuous array of the internal buffer. In the case the <code>circular_buffer</code> is empty the size of the returned array is <code>0</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>array_two() const</code>; <code>array_one()</code> for more details how to pass data into a legacy C API. */ const_array_range array_one() const { return const_array_range(m_first, (m_last <= m_first && !empty() ? m_end : m_last) - m_first); } //! Get the second continuous array of the internal buffer. /*! This method in combination with <code>array_one() const</code> can be useful when passing the stored data into a legacy C API as an array. \return The array range of the second continuous array of the internal buffer. In the case the internal buffer is linear or the <code>circular_buffer</code> is empty the size of the returned array is <code>0</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>array_one() const</code> */ const_array_range array_two() const { return const_array_range(m_buff, m_last <= m_first && !empty() ? m_last - m_buff : 0); } //! Linearize the internal buffer into a continuous array. /*! This method can be useful when passing the stored data into a legacy C API as an array. \post <code>\&(*this)[0] \< \&(*this)[1] \< ... \< \&(*this)[size() - 1]</code> \return A pointer to the beginning of the array or <code>0</code> if empty. \throws <a href="circular_buffer/implementation.html#circular_buffer.implementation.exceptions_of_move_if_noexcept_t">Exceptions of move_if_noexcept(T&)</a>. \par Exception Safety Basic; no-throw if the operations in the <i>Throws</i> section do not throw anything. \par Iterator Invalidation Invalidates all iterators pointing to the <code>circular_buffer</code> (except iterators equal to <code>end()</code>); does not invalidate any iterators if the postcondition (the <i>Effect</i>) is already met prior calling this method. \par Complexity Linear (in the size of the <code>circular_buffer</code>); constant if the postcondition (the <i>Effect</i>) is already met. \warning In general invoking any method which modifies the internal state of the <code>circular_buffer</code> may delinearize the internal buffer and invalidate the returned pointer. \sa <code>array_one()</code> and <code>array_two()</code> for the other option how to pass data into a legacy C API; <code>is_linearized()</code>, <code>rotate(const_iterator)</code> */ pointer linearize() { if (empty()) return 0; if (m_first < m_last || m_last == m_buff) return m_first; pointer src = m_first; pointer dest = m_buff; size_type moved = 0; size_type constructed = 0; BOOST_TRY { for (pointer first = m_first; dest < src; src = first) { for (size_type ii = 0; src < m_end; ++src, ++dest, ++moved, ++ii) { if (moved == size()) { first = dest; break; } if (dest == first) { first += ii; break; } if (is_uninitialized(dest)) { boost::allocator_construct(alloc(), boost::to_address(dest), boost::move_if_noexcept(*src)); ++constructed; } else { value_type tmp = boost::move_if_noexcept(*src); replace(src, boost::move_if_noexcept(*dest)); replace(dest, boost::move(tmp)); } } } } BOOST_CATCH(...) { m_last += constructed; m_size += constructed; BOOST_RETHROW } BOOST_CATCH_END for (src = m_end - constructed; src < m_end; ++src) destroy_item(src); m_first = m_buff; m_last = add(m_buff, size()); #if BOOST_CB_ENABLE_DEBUG invalidate_iterators_except(end()); #endif return m_buff; } //! Is the <code>circular_buffer</code> linearized? /*! \return <code>true</code> if the internal buffer is linearized into a continuous array (i.e. the <code>circular_buffer</code> meets a condition <code>\&(*this)[0] \< \&(*this)[1] \< ... \< \&(*this)[size() - 1]</code>); <code>false</code> otherwise. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>linearize()</code>, <code>array_one()</code>, <code>array_two()</code> */ bool is_linearized() const BOOST_NOEXCEPT { return m_first < m_last || m_last == m_buff; } //! Rotate elements in the <code>circular_buffer</code>. /*! A more effective implementation of <code><a href="https://www.boost.org/sgi/stl/rotate.html">std::rotate</a></code>. \pre <code>new_begin</code> is a valid iterator pointing to the <code>circular_buffer</code> <b>except</b> its end. \post Before calling the method suppose:<br><br> <code>m == std::distance(new_begin, end())</code><br><code>n == std::distance(begin(), new_begin)</code> <br><code>val_0 == *new_begin, val_1 == *(new_begin + 1), ... val_m == *(new_begin + m)</code><br> <code>val_r1 == *(new_begin - 1), val_r2 == *(new_begin - 2), ... val_rn == *(new_begin - n)</code><br> <br>then after call to the method:<br><br> <code>val_0 == (*this)[0] \&\& val_1 == (*this)[1] \&\& ... \&\& val_m == (*this)[m - 1] \&\& val_r1 == (*this)[m + n - 1] \&\& val_r2 == (*this)[m + n - 2] \&\& ... \&\& val_rn == (*this)[m]</code> \param new_begin The new beginning. \throws See <a href="circular_buffer/implementation.html#circular_buffer.implementation.exceptions_of_move_if_noexcept_t">Exceptions of move_if_noexcept(T&)</a>. \par Exception Safety Basic; no-throw if the <code>circular_buffer</code> is full or <code>new_begin</code> points to <code>begin()</code> or if the operations in the <i>Throws</i> section do not throw anything. \par Iterator Invalidation If <code>m \< n</code> invalidates iterators pointing to the last <code>m</code> elements (<b>including</b> <code>new_begin</code>, but not iterators equal to <code>end()</code>) else invalidates iterators pointing to the first <code>n</code> elements; does not invalidate any iterators if the <code>circular_buffer</code> is full. \par Complexity Linear (in <code>(std::min)(m, n)</code>); constant if the <code>circular_buffer</code> is full. \sa <code><a href="https://www.boost.org/sgi/stl/rotate.html">std::rotate</a></code> */ void rotate(const_iterator new_begin) { BOOST_CB_ASSERT(new_begin.is_valid(this)); // check for uninitialized or invalidated iterator BOOST_CB_ASSERT(new_begin.m_it != 0); // check for iterator pointing to end() if (full()) { m_first = m_last = const_cast<pointer>(new_begin.m_it); } else { difference_type m = end() - new_begin; difference_type n = new_begin - begin(); if (m < n) { for (; m > 0; --m) { push_front(boost::move_if_noexcept(back())); pop_back(); } } else { for (; n > 0; --n) { push_back(boost::move_if_noexcept(front())); pop_front(); } } } } // Size and capacity //! Get the number of elements currently stored in the <code>circular_buffer</code>. /*! \return The number of elements stored in the <code>circular_buffer</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>capacity()</code>, <code>max_size()</code>, <code>reserve()</code>, <code>\link resize() resize(size_type, const_reference)\endlink</code> */ size_type size() const BOOST_NOEXCEPT { return m_size; } /*! \brief Get the largest possible size or capacity of the <code>circular_buffer</code>. (It depends on allocator's %max_size()). \return The maximum size/capacity the <code>circular_buffer</code> can be set to. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>size()</code>, <code>capacity()</code>, <code>reserve()</code> */ size_type max_size() const BOOST_NOEXCEPT { return (std::min<size_type>)(boost::allocator_max_size(alloc()), (std::numeric_limits<difference_type>::max)()); } //! Is the <code>circular_buffer</code> empty? /*! \return <code>true</code> if there are no elements stored in the <code>circular_buffer</code>; <code>false</code> otherwise. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>full()</code> */ bool empty() const BOOST_NOEXCEPT { return size() == 0; } //! Is the <code>circular_buffer</code> full? /*! \return <code>true</code> if the number of elements stored in the <code>circular_buffer</code> equals the capacity of the <code>circular_buffer</code>; <code>false</code> otherwise. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>empty()</code> */ bool full() const BOOST_NOEXCEPT { return capacity() == size(); } /*! \brief Get the maximum number of elements which can be inserted into the <code>circular_buffer</code> without overwriting any of already stored elements. \return <code>capacity() - size()</code> \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>capacity()</code>, <code>size()</code>, <code>max_size()</code> */ size_type reserve() const BOOST_NOEXCEPT { return capacity() - size(); } //! Get the capacity of the <code>circular_buffer</code>. /*! \return The maximum number of elements which can be stored in the <code>circular_buffer</code>. \throws Nothing. \par Exception Safety No-throw. \par Iterator Invalidation Does not invalidate any iterators. \par Complexity Constant (in the size of the <code>circular_buffer</code>). \sa <code>reserve()</code>, <code>size()</code>, <code>max_size()</code>, <code>set_capacity(capacity_type)</code> */ capacity_type capacity() const BOOST_NOEXCEPT { return m_end - m_buff; } //! Change the capacity of the <code>circular_buffer</code>. /*! \pre If <code>T</code> is a move only type, then compiler shall support <code>noexcept</code> modifiers and move constructor of <code>T</code> must be marked with it (must not throw exceptions). \post <code>capacity() == new_capacity \&\& size() \<= new_capacity</code><br><br> If the current number of elements stored in the <code>circular_buffer</code> is greater than the desired new capacity then number of <code>[size() - new_capacity]</code> <b>last</b> elements will be removed and the new size will be equal to <code>new_capacity</code>. \param new_capacity The new capacity. \throws "An allocation error" if memory is exhausted, (<code>std::bad_alloc</code> if the standard allocator is used). Whatever <code>T::T(const T&)</code> throws or nothing if <code>T::T(T&&)</code> is noexcept. \par Exception Safety Strong. \par Iterator Invalidation Invalidates all iterators pointing to the <code>circular_buffer</code> (except iterators equal to <code>end()</code>) if the new capacity is different from the original. \par Complexity Linear (in <code>min[size(), new_capacity]</code>). \sa <code>rset_capacity(capacity_type)</code>, <code>\link resize() resize(size_type, const_reference)\endlink</code> */ void set_capacity(capacity_type new_capacity) { if (new_capacity == capacity()) return; pointer buff = allocate(new_capacity); iterator b = begin(); BOOST_TRY { reset(buff, cb_details::uninitialized_move_if_noexcept(b, b + (std::min)(new_capacity, size()), buff, alloc()), new_capacity); } BOOST_CATCH(...) { deallocate(buff, new_capacity); BOOST_RETHROW } BOOST_CATCH_END } //! Change the size of the <code>circular_buffer</code>. /*! \post <code>size() == new_size \&\& capacity() >= new_size</code><br><br> If the new size is greater than the current size, copies of <code>item</code> will be inserted at the <b>back</b> of the of the <code>circular_buffer</code> in order to achieve the desired size. In the case the resulting size exceeds the current capacity the capacity will be set to <code>new_size</code>.<br> If the current number of elements stored in the <code>circular_buffer</code> is greater than the desired new size then number of <code>[size() - new_size]</code> <b>last</b> elements will be removed. (The capacity will remain unchanged.) \param new_size The new size. \param item The element the <code>circular_buffer</code> will be filled with in order to gain the requested size. (See the <i>Effect</i>.) \throws "An allocation error" if memory is exhausted (<code>std::bad_alloc</code> if the standard allocator is used). Whatever <code>T::T(const T&)</code> throws or nothing if <code>T::T(T&&)</code> is noexcept. \par Exception Safety Basic. \par Iterator Invalidation Invalidates all iterators pointing to the <code>circular_buffer</code> (except iterators equal to <code>end()</code>) if the new size is greater than the current capacity. Invalidates iterators pointing to the removed elements if the new size is lower that the original size. Otherwise it does not invalidate any iterator. \par Complexity Linear (in the new size of the <code>circular_buffer</code>). \sa <code>\link rresize() rresize(size_type, const_reference)\endlink</code>, <code>set_capacity(capacity_type)</code> */ void resize(size_type new_size, param_value_type item = value_type()) { if (new_size > size()) { if (new_size > capacity()) set_capacity(new_size); insert(end(), new_size - size(), item); } else { iterator e = end(); erase(e - (size() - new_size), e); } } //! Change the capacity of the <code>circular_buffer</code>. /*! \pre If <code>T</code> is a move only type, then compiler shall support <code>noexcept</code> modifiers and move constructor of <code>T</code> must be marked with it (must not throw exceptions). \post <code>capacity() == new_capacity \&\& size() \<= new_capacity</code><br><br> If the current number of elements stored in the <code>circular_buffer</code> is greater than the desired new capacity then number of <code>[size() - new_capacity]</code> <b>first</b> elements will be removed and the new size will be equal to <code>new_capacity</code>. \param new_capacity The new capacity. \throws "An allocation error" if memory is exhausted (<code>std::bad_alloc</code> if the standard allocator is used). Whatever <code>T::T(const T&)</code> throws or nothing if <code>T::T(T&&)</code> is noexcept. \par Exception Safety Strong. \par Iterator Invalidation Invalidates all iterators pointing to the <code>circular_buffer</code> (except iterators equal to <code>end()</code>) if the new capacity is different from the original. \par Complexity Linear (in <code>min[size(), new_capacity]</code>). \sa <code>set_capacity(capacity_type)</code>, <code>\link rresize() rresize(size_type, const_reference)\endlink</code> */ void rset_capacity(capacity_type new_capacity) { if (new_capacity == capacity()) return; pointer buff = allocate(new_capacity); iterator e = end(); BOOST_TRY { reset(buff, cb_details::uninitialized_move_if_noexcept(e - (std::min)(new_capacity, size()), e, buff, alloc()), new_capacity); } BOOST_CATCH(...) { deallocate(buff, new_capacity); BOOST_RETHROW } BOOST_CATCH_END } //! Change the size of the <code>circular_buffer</code>. /*! \post <code>size() == new_size \&\& capacity() >= new_size</code><br><br> If the new size is greater than the current size, copies of <code>item</code> will be inserted at the <b>front</b> of the of the <code>circular_buffer</code> in order to achieve the desired size. In the case the resulting size exceeds the current capacity the capacity will be set to <code>new_size</code>.<br> If the current number of elements stored in the <code>circular_buffer</code> is greater than the desired new size then number of <code>[size() - new_size]</code> <b>first</b> elements will be removed. (The capacity will remain unchanged.) \param new_size The new size. \param item The element the <code>circular_buffer</code> will be filled with in order to gain the requested size. (See the <i>Effect</i>.) \throws "An allocation error" if memory is exhausted (<code>std::bad_alloc</code> if the standard allocator is used). Whatever <code>T::T(const T&)</code> throws or nothing if <code>T::T(T&&)</code> is noexcept. \par Exception Safety Basic. \par Iterator Invalidation Invalidates all iterators pointing to the <code>circular_buffer</code> (except iterators equal to <code>end()</code>) if the new size is greater than the current capacity. Invalidates iterators pointing to the removed elements if the new size is lower that the original size. Otherwise it does not invalidate any iterator. \par Complexity Linear (in the new size of the <code>circular_buffer</code>). \sa <code>\link resize() resize(size_type, const_reference)\endlink</code>, <code>rset_capacity(capacity_type)</code> */ void rresize(size_type new_size, param_value_type item = value_type()) { if (new_size > size()) { if (new_size > capacity()) set_capacity(new_size); rinsert(begin(), new_size - size(), item); } else { rerase(begin(), end() - new_size); |
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