tdesktop/Telegram/ThirdParty/range-v3/doc/release_notes.md

Release Notes

\section v0-12-0 Version 0.12.0 "Dude, Where's My Bored Ape?"

Released: June 19, 2022

IMPORTANT: This release deprecates views::group_by which was an endless source of confusion. group_by is replaced with views::chunk_by (which, beware, has subtly different semantics, see below.)

Changes:

• NEW: views::chunk_by which, like the old views::group_by it replaces, splits a range into a range-of-ranges, where adjacent elements satisfy a binary predicate (#1648). [Note: Whereas views::group_by evaluated the predicate between the current element and the first element in the chunk, views::chunk_by evaluates the predicate between adjacent elements. -- end note]
• NEW: constexpr all the algorithms that are constexpr in C++20's std::ranges (#1683).
• NEW: Fold algorithms from P2322 (#1628), (#1668).
• NEW: ranges::unformatted_ostream_iterator (#1586).
• NEW: Support for the build2 build system (#1562).
• Implement P2328: relax the constraint on ranges::join_view to support joining ranges of prvalue non-view ranges (#1655).
• Improved algorithm for ranges::linear_distribute (#1679).
• Renamed safe_subrange_t to borrowed_subrange_t (#1542).
• Extend ranges::to to support conversion to container-of-containers (#1553).
• views::enumerate can be a borrowed_view (#1571).
• ranges::upper_bound works in the presence of overloaded operator& (#1632).
• Input iterators are no longer required to be default-constructible (#1652).

Bugs fixed:

• ranges::to<std::map>(v) does not work (#1700)
• ranges::reverse_iterator has the wrong value_type when reversing a proxy range (#1670).
• A post-increment of a ranges::counted_iterator wrapping an input iterator with a void-returning post-increment operator isn't incrementing the count (#1664).
• Bad assert in views::drop_last (#1599).
• Read of uninitialized bool in views::cache1 (#1610).
• ranges::unstable_remove_if calls predicate on same element twice (#1629).
• ranges::on(f,g)(x...) should be f(g(x)...) instead of f(g(x...)) (#1661).
• Broken qualification of cmake targets (#1557).
• Various portability and documentation fixes.

Credits: I would like to thank the following people who contributed to this release (in no particular order): Barry Revzin, @dvirtz, Gonzalo Brito, Johel Ernesto Guerrero Peña, Joël Lamotte, Doug Roeper, Facundo Tuesca, Vitaly Zaitsev, @23rd, @furkanusta, Jonathan Haigh, @SmorkalovG, @marehr, Matt Beardsley, Chris Glover, Louis Dionne, Jin Shang (@js8544), Hui Xie, @huixie90, Robert Maynard, Silver Zachara, @sergegers, Théo DELRIEU, @LesnyRumcajs, Yehezkel Bernat, Maciej Patro, Klemens Nanni, Thomas Madlener, and Jason Merrill.

🎉 Special thanks to Barry Revzin for stepping up to be part-time co-maintainer of range-v3. 🎉

\section v0-11-0 Version 0.11.0 "Thanks, ISO"

Released: August 6, 2020

IMPORTANT: This release removes the heuristic that tries to guess whether a range type is a "view" (lightweight, non-owning range), in accordance with the C++20. This is a potentially source-breaking change. Code that previously used an rvalue range as the start of a pipeline could stop compiling if the range library is not explicitly told that that range type is a view. To override the new default, please specialize the ranges::enable_view<R> Boolean variable template.

IMPORTANT: This release removes the implicit conversion from views to containers. To construct a container from an arbitrary range, you must now explicitly use ranges::to. For example, the following code no longer works:

std::vector<int> is = ranges::views::ints(0, 10); // ERROR: no conversion

Instead, please write this as:

auto is = ranges::views::ints(0, 10) | ranges::to<std::vector>; // OK

ranges::to lives in header <range/v3/range/conversion.hpp>

IMPORTANT: This release drops support for llvm-3.9.

Changes:

• NEW: A new concepts portability layer that short-circuits atomic constraints in requires clauses for better compile times when emulating concepts.
• NEW: Restored support for MSVC in /std:c++17 mode, and for MSVC's default preprocessor.
• Remove the implicit conversion from views to containers.
• Rename the following entities to be consistent with C++20's std::ranges support:
  • safe_range<R> -> borrowed_range<R>
  • enable_safe_range<R> -> enable_borrowed_range<R>
  • safe_iterator_t<R> -> borrowed_iterator_t<R>
  • safe_subrange_t<R> -> borrowed_subrange_t<R>
  • readable_traits<I> -> indirectly_readable_traits<I>
  • readable<I> -> indirectly_readable<I>
  • writable<I> -> indirectly_writable<I>
• Added the following to the ranges::cpp20 namespace:
  • Algorithm for_each_n
  • Algorithm sample
  • Class view_base
  • Alias views::all_t
• Type __int128 is recognized as "integer-like".
• Adds concepts three_way_comparable[_with] when <=> is supported.
• Adds concepts partially_ordered[_with].
• Better conformance with C++20's use of the boolean-testable concept.
• Support C++20 coroutines.
• Honor CMake's CMAKE_CXX_STANDARD variable.
• A fix for the cardinality of views::zip[_with] (#1486).
• Add view_interface::data() member function.
• Add necessary specializations for std::basic_common_reference and std::common_type.
• Numerous workarounds for MSVC.
• Various CMake fixes and improvements.
• drop_while_view is not a sized_range.
• Added support for Wind River Systems.
• Bug fixes to views::group_by (#1393).
• common_[reference|type] of common_[tuple|pair] now yields a common_[tuple|pair] instead of a std::[tuple|pair] (#1422).
• Avoid UB when currying an lvalue in some views and actions (#1320).

Credits: I would like to thank the following people who contributed to this release (in no particular order): Christopher Di Bella, @marehr, Casey Carter, Dvir Yitzchaki, Justin Riddell, Johel Ernesto Guerrero Peña, Barry Revzin, Kamlesh Kumar, and Vincas Dargis.

\section v0-10-0 Version 0.10.0 "To Err is Human"

Released: Dec 6, 2019.

IMPORTANT: Before upgrading, please note that several older compiler versions and build configurations are no longer supported! In particular, MSVC now needs /std:c++latest.

ALSO: When taking a dependency on the range-v3, meta, or concepts libraries via CMake, please now use the namespace qualified target names:

• range-v3::range-v3
• range-v3::meta
• range-v3::concepts

Changes:

• NEW: Rewritten concepts portability layer with simpler macros for better diagnostics.
• NEW: The views::cache1 view caches the most recent value in the range. This can help avoid reevaluation of transformations in complex view pipelines.
• NEW: ranges::contains algorithm.
• NEW: enable_safe_range trait for opting in to the forwarding-range concept. These are ranges whose iterators remain valid even after the range itself has been destroyed; e.g., std::string_view and ranges::subrange.
• The readable concept has changed such that types that are not indirectly readable with operator* (_e.g., std::optional) no longer satisfy that concept.
• Using views::join to join a range of xvalue ranges works again.
• The following range access primitives no longer accept temporary containers (i.e., they refuse to return references known to be dangling):
  • range::front
  • range::back
  • range::at
  • range::index
• views::concat with a single argument now simply returns its argument.
• ranges::ostream_iterator<T> now coerces arguments to T before inserting them into the wrapped ostream.
• Smaller iterators for views::transform and views::take_while.
• actions::split and actions::split_when now support partial application and pipelining (#1085).
• views::group_by and its iterator both get a .base() member to access the underlying range and iterator, respectively.
• Improved diagnostics with clang.
• Assorted bug fixes and compiler work-arounds: #284, #491, #499, #871, #1022, #1043, #1081, #1085, #1101, #1116, #1296, #1305, and #1335.

Many thanks to GitHub users @CaseyCarter, @morinmorin, @h-2, @MichaelWJung, @johelegp, @marehr, @alkino, @xuning97, @BRevzin, and @mpusz for their contributions.

\section v0-9-1 Version 0.9.1

Released: Sept 1, 2019.

gcc-9.x portability fixes.

\section v0-9-0 Version 0.9.0 "Std::ranger Things"

Released: Aug 26, 2019.

Bring many interfaces into sync with the C++20 draft.

• NEW: An improved concepts portability layer with macros that use C++20 concepts when the compiler supports them.
• NEW: An improved directory structure that keeps disjoint parts of the library -- iterators, ranges, algorithms, actions, views, functional programming support, and general utilities -- physically separate.
• NEW: A RANGES_DEEP_STL_INTEGRATION configuration option that makes your STL implementation default to structural conformance to infer iterator category, as in C++20. Applies to libc++, libstdc++, and MSVC's Standard Library.
• NEW: A ranges::cpp20 namespace that contains all the functionality of C++20's std::ranges namespace.
• All concept names have been given standard_case (renamed from PascalCase) and have been harmonized with the C++20 draft.
• The following range access customization points no longer accept rvalue ranges by default:
  • ranges::begin
  • ranges::end
  • ranges::rbegin
  • ranges::rend
  • ranges::cbegin
  • ranges::cend
  • ranges::crbegin
  • ranges::crend
  • ranges::data
  • ranges::cdata
• Iterators may specify an iterator_concept type alias in addition to iterator_category -- either as a nested type or as a member of a std::iterator_traits specialization -- to denote conformance to the C++20 iterator concepts as distinct from the C++98 iterator requirements. (See P1037 "Deep Integration of the Ranges TS" for more information.)
• The ranges::value_type trait has been renamed to readable_traits.
• The ranges::difference_type trait has been renamed to incrementable_traits.
• The ranges::iterator_category trait has been deprecated. Specialize std::iterator_traits to non-intrusively specify an iterator's category and (optionally) concept.
• Rename the ranges::view namespace to ranges::views and ranges::action to ranges::actions (with deprecated namespace aliases for migration).
• Rename view::bounded to views::common.
• Rename unreachable to unreachable_sentinel_t.
• Change dangling from a class template that wraps an iterator to a class that acts as a placeholder for an iterator that would otherwise dangle.
• Implement C++20's subrange as a view that wraps an iterator/sentinel pair; deprecate iterator_range.
• Deprecate implicit conversion from view types to containers; rename ranges::to_ to ranges::to and extend it to support converting a range-of-ranges to a container-of-containers.
• Deprecate the ranges::v3 inline versioning namespace.
• The following views have had minor changes to bring them into conformance with the C++20 working draft:
  • join_view
  • single_view
  • empty_view
  • split_view
  • reverse_view
  • all_view
  • take_view
  • iota_view

  `iota_view`, in particular, is given a user-defined `difference_type` that avoids integer overflow.

• New names for the iterator and range type aliases:

  Old Name	New Name
  value_type_t	iter_value_t
  reference_t	iter_reference_t
  difference_type_t	iter_difference_t
  size_type_t	deprecated
  rvalue_reference_t	iter_rvalue_reference_t
  range_value_type_t	range_value_t
  range_difference_type_t	range_difference_t
  range_size_type_t	range_size_t

\section v0-5-0 Version 0.5.0

Released: Apr 30, 2019.

• NEW: MSVC support, from @CaseyCarter 🎉 (See the docs for the list of supported compilers.)
• NEW: view::enumerate, from @MikeGitb
• NEW: view::addressof, from @tower120
• NEW: unstable_remove_if algorithm and action, from @tower120
• NEW: adjacent_remove_if algorithm and action, from @cjdb
• NEW: ostream_joiner, from @sv1990
• view::drop_while and view::take_while get projection support, from @mrpi
• view::filter and view::remove_if get projection support, from @mrpi
• view::unique accepts optional comparison operator, from @tete17
• action::slice supports sliding from the end, from @tete17
• Support coroutines on MSVC, from @CaseyCarter
• Faster view::generate_n, from GitHub user @tower120
• Improved aligned new detection for libc++ on iOS, from @mtak-
• Various CMake improvements, from @johelegp
• view_adaptor supports basic_iterator-style mixins, from @tower120
• Fix ranges::advance for random-access iterators for n==0, from @tower120
• Bugs fixed: #755, #759, #942, #946, #952, #975, #978, #986, #996, #1041, #1047, #1088, #1094, #1107, #1129

\section v0-4-0 Version 0.4.0

Released: Oct 18, 2018.

• Minor interface-breaking changes:
  • single_view returns by const & (see #817).
  • reverse_view of a non-Sized, non-Bounded RandomAccess range (eg., a null-terminated string) no longer satisfies SizedRange.
  • The generate and generate_n views now return the generated values by xvalue reference (T &&) to the value cached within the view (see #905).
  • Views no longer prefer returning constant iterators when they can; some views have different constant and mutable iterators.
• Enhancements:
  • Views can successfully adapt other views that have different constant and mutable iterators.
  • The single and empty views are much closer to the versions as specified in P0896.
• Bug fixes:
  • "single_view should not copy the value" #817.
  • "Calling back() on strided range does not return the correct last value in range" #901.
  • "generate(foo) | take(n) calls foo n+1 times" #819.
  • "generate seems broken with move-only return types" #905.
  • "Unexpected behavior in generate with return by reference" #807.
  • "Inconsistent behaviour of ranges::distance with ranges::view::zip using infinite views." #783.
  • "Infinite loop when using ranges::view::cycle with an infinite range" #780.
  • "Composing ranges::view::cycle with ranges::view::slice" #778.
  • "cartesian_product view, now with moar bugs." #919.

\section v0-3-7 Version 0.3.7

Released: Sept 19, 2018.

• Improved support for clang-cl (thanks to @CaseyCarter).
• Fix for any_view<T, category::sized | category::input> (see #869).
• Fix iter_move of a ranges::reverse_iterator (see #888).
• Fix move_sentinel comparisons (see #889).
• Avoid ambiguity created by boost::advance and std::advance (see #893).

\section v0-3-6 Version 0.3.6

Released: May 15, 2018.

• NEW: view::exclusive_scan (thanks to GitHub user @mitsutaka-takeda).
• All views get non-const overloads of .empty() and .size() (see ericniebler/stl2#793).
• Upgrade Conan support for conan 1.0.
• subspan interface tweaks.
• Fix bug in view::split (see this stackoverflow question).
• Fix bug in view::stride (see ericniebler/stl2#805).
• Fix const-correctness problem in view::chunk (see this stackoverflow question).
• Replace uses of ranges::result_of with ranges::invoke_result.
• Fix potential buffer overrun of view::drop over RandomAccessRanges.
• Lots of view::cartesian_product fixes (see ericniebler/stl2#820, ericniebler/stl2#823).
• Work around gcc-8 regression regarding volatile std::initializer_lists (see ericniebler/stl2#826).
• Fix const-correctness problem of view::take.

\section v0-3-5 Version 0.3.5

Released: February 17, 2018.

• Rvalues may satisfy Writable (see ericniebler/stl2#387).
• view_interface gets a bounds-checking at method.
• chunk_view works on Input ranges.
• Fix bug in group_by_view.
• Improved concept checks for partial_sum numeric algorithm.
• Define ContiguousIterator concept and contiguous_iterator_tag iterator category tag.
• Sundry span fixes.
• action::insert avoids interfering with vector's exponentional growth strategy.
• Add an experimental shared view for views that need container-like scratch space to do their work.
• Faster, simpler reverse_view.
• Rework ranges::reference_wrapper to avoid LWG#2993.
• Reworked any_view, the type-erased view wrapper.
• equal algorithm is constexpr in C++14.
• stride_view no longer needs an atomic data member.
• const-correct drop_view.
• adjacent_filter_view supports bidirectional iteration.
• Massive view_adaptor cleanup to remove the need for a mutable data member holding the adapted view.
• Fix counting_iterator post-increment bug.
• tail_view of an empty range is an empty range, not undefined behavior.
• Various portability fixes for gcc and clang trunk.

\section v0-3-0 Version 0.3.0

Released: June 30, 2017.

• Input views may now be move-only (from @CaseyCarter)
• Input any_views are now much more efficient (from @CaseyCarter)
• Better support for systems lacking a working <thread> header (from @CaseyCarter)

\section v0-2-6 Version 0.2.6

Released: June 21, 2017.

• Experimental coroutines with ranges::experimental::generator (from @CaseyCarter)
• ranges::optional now behaves like std::optional (from @CaseyCarter)
• Extensive bug fixes with Input ranges (from @CaseyCarter)

\section v0-2-5 Version 0.2.5

Released: May 16, 2017.

• view::chunk works on Input ranges (from @CaseyCarter)
• for_each_n algorithm (from @khlebnikov)
• Portability fixes for MinGW, clang-3.6 and -3.7, and gcc-7; and cmake 3.0

\section v0-2-4 Version 0.2.4

Released: April 12, 2017.

Fix the following bug:

• action::stable_sort of vector broken on Clang 3.8.1 since ~last Xmas (ericniebler/range-v3#632).

\section v0-2-3 Version 0.2.3

Released: April 4, 2017.

Fix the following bug:

• iterators that return move-only types by value do not satisfy Readable (ericniebler/stl2#399).

\section v0-2-2 Version 0.2.2

Released: March 30, 2017.

New in this release:

• view::linear_distribute(from,to,n) - A view of n elements between from and to, distributed evenly.
• view::indices(n) - A view of the indices [0,1,2...n-1].
• view::closed_indices(n) - A view of the indices [0,1,2...n].

This release deprecates view::ints(n) as confusing to new users.

\section v0-2-1 Version 0.2.1

Released: March 22, 2017.

New in this release:

• view::cartesian_product
• action::reverse

\section v0-2-0 Version 0.2.0

Released: March 13, 2017.

Bring many interfaces into sync with the Ranges TS.

• Many interfaces are simply renamed. The following table shows the old names and the new. (All names are in the ranges::v3 namespace.)

  Old Name	New Name
  indirect_swap	iter_swap
  indirect_move	iter_move
  iterator_value_t	value_type_t
  iterator_reference_t	reference_t
  iterator_difference_t	difference_type_t
  iterator_size_t	size_type_t
  iterator_rvalue_reference_t	rvalue_reference_t
  iterator_common_reference_t	iter_common_reference_t
  range_value_t	range_value_type_t
  range_difference_t	range_difference_type_t
  range_size_t	range_size_type_t
  range_iterator_t	iterator_t
  range_sentinel_t	sentinel_t

• common_iterator now requires that its two types (Iterator and Sentinel) are different. Use common_iterator_t<I, S> to get the old behavior (i.e., if the two types are the same, it is an alias for I; otherwise, it is common_iterator<I, S>).

• The following iterator adaptors now work with iterators that return proxies from their postfix increment operator (i.e., operator++(int)):

  • common_iterator
  • counted_iterator

• The following customization points are now implemented per the Ranges TS spec and will no longer find the associated unconstrained overload in namespace std:::

  • ranges::begin
  • ranges::end
  • ranges::size
  • ranges::swap
  • ranges::iter_swap

  (In practice, this has very little effect but it may effect overloading in rare situations.)

• ranges::is_swappable now only takes one template parameter. The new ranges::is_swappable_with<T, U> tests whether T and U are swappable. ranges::is_swappable<T> is equivalent to ranges::is_swappable_with<T &, T &>.

• The following object concepts have changed to conform with the Ranges TS specification, and approved changes (see P0547):

  • Destructible
  • Constructible
  • DefaultConstructible
  • MoveConstructible
  • MoveConstructible
  • Movable
  • Assignable

• The View concept is no longer satisfied by reference types.

• The syntax for defining a concept has changed slightly. See iterator/concepts.hpp for examples.

\section v0-1-1 Version 0.1.1

• Small tweak to Writable concept to fix #537.

\section v0-1-0 Version 0.1.0

• March 8, 2017, Begin semantic versioning