Build nvforest with C++20

[csadorf]

Change the nvforest C++ and CUDA build standards from C++17 to C++20.

Closes #122

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Run ID: 0d151863-da34-4a9e-8777-71ca33abbe22

📥 Commits

Reviewing files that changed from the base of the PR and between b3bdd26 and 40046e5.

📒 Files selected for processing (1)

• cpp/scripts/run-clang-tidy.py

🚧 Files skipped from review as they are similar to previous changes (1)

• cpp/scripts/run-clang-tidy.py

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📝 Walkthrough

Summary by CodeRabbit

• Chores
  • Upgraded C++ and CUDA compiler language standards from 17 to 20 across build and test configurations.
  • Updated static-analysis tooling to use the newer language standard and to exclude unsupported compiler flags during linting.

Walkthrough

Bumps C++ and CUDA language standards from 17 to 20 for library and tests, and updates run-clang-tidy.py to use -std=c++20 and to filter unsupported clang flags from generated clang-tidy invocations.

Changes

Language Standard & Tooling

Layer / File(s)	Summary
Language standard updates for nvforest++ and test targets cpp/CMakeLists.txt, cpp/tests/CMakeLists.txt	The CXX_STANDARD and CUDA_STANDARD target properties are updated from 17 to 20 for both the main nvforest++ library target and the test targets; CXX_STANDARD_REQUIRED remains enabled.
clang-tidy invocation sanitization cpp/scripts/run-clang-tidy.py	Adds UNSUPPORTED_CLANG_FLAGS, implements remove_unsupported_clang_flags(command), updates normalized compile args to use -std=c++20, strips -c/-o, and removes unsupported flags before invoking clang-tidy.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• rapidsai/nvforest#100: Related to clang tooling/version changes and integration with formatting/clang tooling.

Suggested reviewers

• dantegd

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately and concisely summarizes the main change: upgrading the build standards from C++17 to C++20.
Description check	✅ Passed	The description directly relates to the changeset, explaining the C++17 to C++20 migration and referencing the linked issue.
Linked Issues check	✅ Passed	All coding requirements from issue #122 are met: C++ and CUDA standards updated to 20 in CMakeLists.txt files and clang-tidy script.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to the C++20 migration objective; no out-of-scope modifications are present.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch issue-122-port-nvforest-c-build-to-c-20

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[hcho3]

/merge