ericniebler/range-v3 0.11.0

Thanks, ISO

on GitHub

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.