Prepare for release v2.2

Author: vgvassilev

VERSION

@@ -1 +1 @@
-2.2.0~dev
+2.2.0

docs/ReleaseNotes.md

@@ -21,42 +21,93 @@ described first.
 External Dependencies
 ---------------------
 
-* Clad now works with clang-10 to clang-20
+* Clad now works with clang-11 to clang-21
+* Removed unused coverage libraries for faster CI builds.
+* Fixed Python 3.12 linking issue in LLVM 16 installs on macOS.
+* macOS ARM CI updated to macOS 26.
 
 
 Forward Mode & Reverse Mode
 ---------------------------
-*
+
+* Major internal cleanup and generalization of differentiation pipelines.
+* Unified initialization logic for adjoints and original variables.
+* Improved compatibility across pointer, tensor, and reference types.
+* Added support for conversion operators and `std::reference_wrapper`.
+* Enhanced handling of initialization lists, pseudo-destructors, and complex
+  expressions.
+
 
 Forward Mode
 ------------
-*
+
+* OpenMP Support (Experimental): Introduced basic OpenMP support for forward
+  mode differentiation.
+* Simplified adjoint and initializer handling for forward-pass variables.
 
 Reverse Mode
 ------------
-*
+
+* Added reverse mode checkpointing for loops, improving memory efficiency in
+  long iterations.
+* Elidable Reverse Passes: Introduced `elidable_reverse_forw` attribute to skip
+  redundant reverse passes for trivially invertible functions.
+* `constructor_reverse_forw` now supports static scheduling and
+  `elidable_reverse_forw`.
+* Added support for `CompoundLiteralExpr` and improved differentiation through
+  compound expressions.
+* Simplified handling of deallocations and memory operations via attributes.
+* Improved function differentiation sequence by resolving pullbacks before
+  argument differentiation.
+* Unified differentiation order for pointer and reference types.
+* Optimized unary operator simplification (removed redundant &*_d_x patterns).
+
 
 CUDA
 ----
-*
 
-Error Estimation
-----------------
-*
+* Extended Thrust differentiation support:
+  - `thrust::reduce_by_key`
+  - `thrust::sort_by_key`
+  - `thrust::adjacent_difference`
+  - segmented scans and prefix-sum operations
+* Added thrust::device_vector support.
+* Introduced BoW (Bag-of-Words) logistic regression demo using Thrust.
+* Replaced iterator-based std::move with CUDA-safe clad::move.
+* Added generic functor support for Thrust transform.
+
 
 Misc
 ----
-*
+
+* Added thread-safe tape access functions:
+  - Zero overhead in single-threaded mode.
+  - Controlled locking for multithreaded differentiation.
+* Improved handling of ill-formed code by skipping Clad runs when Clang
+  compilation fails.
+* Refined diagnostic messages and simplified deallocation functions through
+  attribute-based design.
+* Updated testing and build infrastructure:
+  - Added STL test coverage (starting with <cmath>).
+  - Cleaned up coverage configuration.
+  - Enhanced CI stability and performance.
 
 Fixed Bugs
 ----------
 
-[XXX](https://github.com/vgvassilev/clad/issues/XXX)
+[679](https://github.com/vgvassilev/clad/issues/679)
+[1413](https://github.com/vgvassilev/clad/issues/1413)
+[1482](https://github.com/vgvassilev/clad/issues/1482)
+[1496](https://github.com/vgvassilev/clad/issues/1496)
+[1521](https://github.com/vgvassilev/clad/issues/1521)
+[1522](https://github.com/vgvassilev/clad/issues/1522)
 
  <!---Get release bugs. Check for close, fix, resolve
  git log v2.1..master | grep -i "close" | grep '#' | sed -E 's,.*\#([0-9]*).*,\[\1\]\(https://github.com/vgvassilev/clad/issues/\1\),g' | sort -t'[' -k2,2n
  --->
 
+<!--- https://github.com/vgvassilev/clad/issues?q=is%3Aissue%20state%3Aclosed%20closed%3A%3E2025-10-01 --->
+
 Special Kudos
 =============
 
@@ -67,6 +118,14 @@ FirstName LastName (#commits)
 
 A B (N)
 
+Petro Zarytskyi (33; reverse mode, loop checkpointing, elidable reverse passes)
+Abdelrhman Elrawy (9; CUDA/Thrust derivatives, demos, logistic regression)
+Vassil Vassilev (9; compiler integration, CI, and build infrastructure)
+Matthew Barton (2; macOS and Python 3.12 CI fixes)
+Aditi Joshi (1; thread-safe tape access implementation)
+Max Andriychuk (1; analyses)
+Errant (1; OpenMP differentiation support)
+
 <!---Find contributor list for this release
  git log --pretty=format:"%an"  v2.1...master | sort | uniq -c | sort -rn | sed -E 's,^ *([0-9]+) (.*)$,\2 \(\1\),'
 --->