[libc++] Implement P2242R1 std::views::chunk

This PR implements libc++ `std::ranges::chunk_view` in header
<__ranges/chunk_view.h>.

We also provide several unit tests in
`libcxx/test/std/ranges/range.adaptors/range.chunk/`.

Author: anonymouspc

libcxx/docs/FeatureTestMacroTable.rst

@@ -370,7 +370,7 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_ranges_as_rvalue``                             ``202207L``
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_ranges_chunk``                                 *unimplemented*
+    ``__cpp_lib_ranges_chunk``                                 ``202202L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_ranges_chunk_by``                              ``202202L``
     ---------------------------------------------------------- -----------------

libcxx/docs/ReleaseNotes/22.rst

@@ -49,6 +49,7 @@ Implemented Papers
 - P2835R7: Expose ``std::atomic_ref``'s object address (`Github <https://llvm.org/PR118377>`__)
 - P2944R3: Comparisons for ``reference_wrapper`` (`Github <https://llvm.org/PR105424>`__)
 - P3168R2: Give ``std::optional`` Range Support (`Github <https://llvm.org/PR105430>`__)
+- P2442R1: Add ``std::views::chunk`` (`Github <https://llvm.org/PR171109>`__)
 
 Improvements and New Features
 -----------------------------

libcxx/docs/Status/Cxx23Papers.csv

@@ -48,8 +48,8 @@
 "`P2387R3 <https://wg21.link/P2387R3>`__","Pipe support for user-defined range adaptors","2022-02 (Virtual)","|Complete|","19","`#105183 <https://github.com/llvm/llvm-project/issues/105183>`__",""
 "`P2440R1 <https://wg21.link/P2440R1>`__","``ranges::iota``, ``ranges::shift_left`` and ``ranges::shift_right``","2022-02 (Virtual)","|Partial|","","`#105184 <https://github.com/llvm/llvm-project/issues/105184>`__","Only ``ranges::iota`` is implemented."
 "`P2441R2 <https://wg21.link/P2441R2>`__","``views::join_with``","2022-02 (Virtual)","|Complete|","21","`#105185 <https://github.com/llvm/llvm-project/issues/105185>`__",""
-"`P2442R1 <https://wg21.link/P2442R1>`__","Windowing range adaptors: ``views::chunk`` and ``views::slide``","2022-02 (Virtual)","","","`#105187 <https://github.com/llvm/llvm-project/issues/105187>`__",""
-"`P2443R1 <https://wg21.link/P2443R1>`__","``views::chunk_by``","2022-02 (Virtual)","|Complete|","18","`#105188 <https://github.com/llvm/llvm-project/issues/105188>`__",""
+"`P2442R1 <https://wg21.link/P2442R1>`__","Windowing range adaptors: ``views::chunk`` and ``views::slide``","2022-02 (Virtual)","|Partial|","22","`#105187 <https://github.com/llvm/llvm-project/issues/105187>`__",""
+"`P2443R1 <https://wg21.link/P2443R1>`__","``views::chunk_by``","2022-02 (Virtual)","|Complete|","18","`#105188 <https://github.com/llvm/llvm-project/issues/105188>`__","Only ``views::chunk`` is implemented."
 "","","","","","",""
 "`P0009R18 <https://wg21.link/P0009R18>`__","mdspan: A Non-Owning Multidimensional Array Reference","2022-07 (Virtual)","|Complete|","18","`#105189 <https://github.com/llvm/llvm-project/issues/105189>`__",""
 "`P0429R9 <https://wg21.link/P0429R9>`__","A Standard ``flat_map``","2022-07 (Virtual)","|Complete|","20","`#105190 <https://github.com/llvm/llvm-project/issues/105190>`__",""

libcxx/include/CMakeLists.txt

@@ -703,6 +703,7 @@ set(files
   __ranges/all.h
   __ranges/as_rvalue_view.h
   __ranges/chunk_by_view.h
+  __ranges/chunk_view.h
   __ranges/common_view.h
   __ranges/concepts.h
   __ranges/container_compatible_range.h

libcxx/include/__cxx03/module.modulemap

@@ -1701,6 +1701,7 @@ module cxx03_std_private_ranges_all                        [system] {
 }
 module cxx03_std_private_ranges_as_rvalue_view             [system] { header "__ranges/as_rvalue_view.h" }
 module cxx03_std_private_ranges_chunk_by_view              [system] { header "__ranges/chunk_by_view.h" }
+module cxx03_std_private_ranges_chunk_view                 [system] { header "__ranges/chunk_view.h" }
 module cxx03_std_private_ranges_common_view                [system] { header "__ranges/common_view.h" }
 module cxx03_std_private_ranges_concepts                   [system] {
   header "__ranges/concepts.h"