Remove use of std::aligned_storage in any.hpp

[nyibbang]

Summary

This change removes the use of the std::aligned_storage type in contrib/any.hpp and replaces it with a struct with an explicit alignment requirement inheriting an array of bytes of the right size.

Motivation

The std::aligned_storage type has been deprecated in C++23, which may cause warnings in client code using the any.hpp header directly or indirectly.

References for this change are this stackoverflow discussion and the paper P1413R3 that suggested the deprecation.

In that paper, the suggested change is the following:

- std::aligned_storage_t<sizeof(T), alignof(T)> t_buff;
+ alignas(T) std::byte t_buff[sizeof(T)];

However in the context of the library and its clang-tidy rules (in this case, modernize-* rules) generate a warning with C-arrays and advise using a std::array instead.

Impacts on API / ABI

There is no impact on API, and as far as I know it should be ABI compatible.

Summary by CodeRabbit

• Refactor
  • Improved internal storage implementation to enhance memory alignment handling.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

📝 Walkthrough

Walkthrough

The any.hpp header file's internal stack storage type is refactored, replacing std::aligned_storage-based definition with a struct-based approach that inherits from std::array<std::byte>, including a new #include <array> directive to support this change.

Changes

Cohort / File(s)	Change Summary
Stack Storage Type Refactoring include/behaviortree_cpp/contrib/any.hpp	Replaced std::aligned_storage-based stack_storage_t type alias with a struct-based definition using alignas(void*) and std::array<std::byte, 2 * sizeof(void*)> inheritance. Added #include <array> directive.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 A rabbit hops through storage so deep,
Where bytes align and secrets keep,
From ancient aligned_storage we part,
Array-based structs now play the part,
Cleaner casting, a modernized art! 📦

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: removing std::aligned_storage from any.hpp, which is the primary objective of the PR.
Description check	✅ Passed	The description provides a clear summary, motivation with references, and documents API/ABI impacts, meeting the template requirements despite minor variations in section naming.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}