Released: June 19, 2022
IMPORTANT: This release deprecates
views::group_bywhich was an endless source of confusion.group_byis replaced withviews::chunk_by(which, beware, has subtly different semantics, see below.)
Changes:
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]constexpr all the algorithms that are constexpr in C++20's std::ranges (#1683).ranges::unformatted_ostream_iterator (#1586).build2 build system (#1562).ranges::join_view to support joining ranges of prvalue non-view ranges (#1655).ranges::linear_distribute (#1679).safe_subrange_t to borrowed_subrange_t (#1542).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).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).ranges::counted_iterator wrapping an input iterator with a void-returning post-increment operator isn't incrementing the count (#1664).views::drop_last (#1599).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).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. 🎉
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:
{c++}std::vector<int> is = ranges::views::ints(0, 10); // ERROR: no conversionInstead, please write this as:
{c++}auto is = ranges::views::ints(0, 10) | ranges::to<std::vector>; // OK
ranges::tolives in header<range/v3/range/conversion.hpp>
IMPORTANT: This release drops support for llvm-3.9.
Changes:
requires clauses for better compile times when emulating concepts./std:c++17 mode, and for MSVC's default preprocessor.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>ranges::cpp20 namespace:for_each_nsampleview_baseviews::all_t__int128 is recognized as "integer-like".three_way_comparable[_with] when <=> is supported.partially_ordered[_with].boolean-testable_ concept.CMAKE_CXX_STANDARD variable.views::zip[_with] (#1486).view_interface::data() member function.std::basic_common_reference and std::common_type.drop_while_view is not a sized_range.views::group_by (#1393).common_[reference|type] of common_[tuple|pair] now yields a common_[tuple|pair] instead of a std::[tuple|pair] (#1422).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.
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-v3range-v3metarange-v3::conceptsChanges:
views::cache1 view caches the most recent value in the range. This can help avoid reevaluation of transformations in complex view pipelines.ranges::contains algorithm.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.readable concept has changed such that types that are not indirectly readable with operator* (e.g., std::optional) no longer satisfy that concept.views::join to join a range of xvalue ranges works again.range::frontrange::backrange::atrange::indexviews::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.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.Many thanks to GitHub users @CaseyCarter, @morinmorin, @h-2, @MichaelWJung, @johelegp, @marehr, @alkino, @xuning97, @BRevzin, and @mpusz for their contributions.
Released: Sept 1, 2019.
gcc-9.x portability fixes.
Released: Aug 26, 2019.
Bring many interfaces into sync with the C++20 draft.
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.ranges::cpp20 namespace that contains all the functionality of C++20's std::ranges namespace.ranges::beginranges::endranges::rbeginranges::rendranges::cbeginranges::cendranges::crbeginranges::crendranges::dataranges::cdataiterator_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.)ranges::value_type trait has been renamed to readable_traits.ranges::difference_type trait has been renamed to incrementable_traits.ranges::iterator_category trait has been deprecated. Specialize std::iterator_traits to non-intrusively specify an iterator's category and (optionally) concept.ranges::view namespace to ranges::views and ranges::action to ranges::actions (with deprecated namespace aliases for migration).view::bounded to views::common.unreachable to unreachable_sentinel_t.dangling from a class template that wraps an iterator to a class that acts as a placeholder for an iterator that would otherwise dangle.subrange as a view that wraps an iterator/sentinel pair; deprecate iterator_range.ranges::to_ to ranges::to and extend it to support converting a range-of-ranges to a container-of-containers.ranges::v3 inline versioning namespace.The following views have had minor changes to bring them into conformance with the C++20 working draft:
join_viewsingle_viewempty_viewsplit_viewreverse_viewall_viewtake_viewiota_view iota_view<std::[u]intmax_t>, in particular, is given a user-defined difference_type that avoids integer overflow.
| 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 |
Released: Apr 30, 2019.
view::enumerate, from @MikeGitbview::addressof, from @tower120unstable_remove_if algorithm and action, from @tower120adjacent_remove_if algorithm and action, from @cjdbostream_joiner, from @sv1990view::drop_while and view::take_while get projection support, from @mrpiview::filter and view::remove_if get projection support, from @mrpiview::unique accepts optional comparison operator, from @tete17action::slice supports sliding from the end, from @tete17view::generate_n, from GitHub user @tower120view_adaptor supports basic_iterator-style mixins, from @tower120ranges::advance for random-access iterators for n==0, from @tower120Released: Oct 18, 2018.
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.generate and generate_n views now return the generated values by xvalue reference (T &&) to the value cached within the view (see #905).single and empty views are much closer to the versions as specified in P0896.Released: Sept 19, 2018.
any_view<T, category::sized | category::input> (see #869).iter_move of a ranges::reverse_iterator (see #888).move_sentinel comparisons (see #889).boost::advance and std::advance (see #893).Released: May 15, 2018.
view::exclusive_scan (thanks to GitHub user @mitsutaka-takeda).const overloads of .empty() and .size() (see ericniebler/stl2#793).subspan interface tweaks.view::split (see this stackoverflow question).view::stride (see ericniebler/stl2#805).const-correctness problem in view::chunk (see this stackoverflow question).ranges::result_of with ranges::invoke_result.view::drop over RandomAccessRanges.view::cartesian_product fixes (see ericniebler/stl2#820, ericniebler/stl2#823).volatile std::initializer_lists (see ericniebler/stl2#826).const-correctness problem of view::take.Released: February 17, 2018.
Writable (see ericniebler/stl2#387).view_interface gets a bounds-checking at method.chunk_view works on Input ranges.group_by_view.partial_sum numeric algorithm.ContiguousIterator concept and contiguous_iterator_tag iterator category tag.span fixes.action::insert avoids interfering with vector's exponentional growth strategy.shared view for views that need container-like scratch space to do their work.reverse_view.ranges::reference_wrapper to avoid LWG#2993.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.view_adaptor cleanup to remove the need for a mutable data member holding the adapted view.counting_iterator post-increment bug.tail_view of an empty range is an empty range, not undefined behavior.Released: June 30, 2017.
any_views are now much more efficient (from @CaseyCarter)<thread> header (from @CaseyCarter)Released: June 21, 2017.
ranges::experimental::generator (from @CaseyCarter)ranges::optional now behaves like std::optional (from @CaseyCarter)Released: May 16, 2017.
view::chunk works on Input ranges (from @CaseyCarter)for_each_n algorithm (from @khlebnikov)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).Released: April 4, 2017.
Fix the following bug:
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.
Released: March 22, 2017.
New in this release:
view::cartesian_productaction::reverseReleased: March 13, 2017.
Bring many interfaces into sync with the Ranges TS.
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>).operator++(int)):common_iteratorcounted_iteratorThe following customization points are now implemented per the Ranges TS spec and will no longer find the associated unconstrained overload in namespace std:::
ranges::beginranges::endranges::sizeranges::swapranges::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 &>.DestructibleConstructibleDefaultConstructibleMoveConstructibleMoveConstructibleMovableAssignableView concept is no longer satisfied by reference types.Writable concept to fix #537.