[libc++] implement adjacent_view

Author: huixie90

libcxx/docs/ReleaseNotes/22.rst

@@ -39,7 +39,7 @@ Implemented Papers
 ------------------
 
 - P2321R2: ``zip`` (`Github <https://llvm.org/PR105169>`__) (The paper is partially implemented. ``zip_transform_view``
-  is implemented in this release)
+  and `adjacent_view` are implemented in this release)
 - P3044R2: sub-``string_view`` from ``string`` (`Github <https://llvm.org/PR148140>`__)
 - P3223R2: Making ``std::istream::ignore`` less surprising (`Github <https://llvm.org/PR148178>`__)
 - P3060R3: Add ``std::views::indices(n)`` (`Github <https://llvm.org/PR148175>`__)

libcxx/include/CMakeLists.txt

@@ -696,6 +696,7 @@ set(files
   __random/uniform_real_distribution.h
   __random/weibull_distribution.h
   __ranges/access.h
+  __ranges/adjacent_view.h
   __ranges/all.h
   __ranges/as_rvalue_view.h
   __ranges/chunk_by_view.h
@@ -739,6 +740,7 @@ set(files
   __ranges/view_interface.h
   __ranges/views.h
   __ranges/zip_transform_view.h
+  __ranges/zip_utils.h
   __ranges/zip_view.h
   __split_buffer
   __std_mbstate_t.h