EXP: [C++] Require C++20

[pitrou]

Rationale for this change

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[github-actions]

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[pitrou]

@github-actions crossbow submit -g cpp -g python

[pitrou]

@github-actions crossbow submit -g cpp -g python -g wheel

[github-actions]

Revision: 318b69a

Submitted crossbow builds: ursacomputing/crossbow @ actions-433ce83702

Task	Status
example-cpp-minimal-build-static
example-cpp-minimal-build-static-system-dependency
example-cpp-tutorial
example-python-minimal-build-fedora-conda
example-python-minimal-build-ubuntu-venv
python-sdist
test-alpine-linux-cpp
test-build-cpp-fuzz
test-conda-cpp
test-conda-cpp-valgrind
test-conda-python-3.10
test-conda-python-3.10-hdfs-2.9.2
test-conda-python-3.10-hdfs-3.2.1
test-conda-python-3.10-pandas-latest-numpy-latest
test-conda-python-3.10-substrait
test-conda-python-3.11
test-conda-python-3.11-dask-latest
test-conda-python-3.11-dask-upstream_devel
test-conda-python-3.11-hypothesis
test-conda-python-3.11-pandas-latest-numpy-1.26
test-conda-python-3.11-pandas-latest-numpy-latest
test-conda-python-3.11-pandas-nightly-numpy-nightly
test-conda-python-3.11-pandas-upstream_devel-numpy-nightly
test-conda-python-3.11-spark-master
test-conda-python-3.12
test-conda-python-3.12-cpython-debug
test-conda-python-3.13
test-conda-python-3.9
test-conda-python-3.9-pandas-1.1.3-numpy-1.19.5
test-conda-python-emscripten
test-cuda-cpp-ubuntu-20.04-cuda-11.2.2
test-cuda-cpp-ubuntu-22.04-cuda-11.7.1
test-cuda-python-ubuntu-22.04-cuda-11.7.1
test-debian-12-cpp-amd64
test-debian-12-cpp-i386
test-debian-12-python-3-amd64
test-debian-12-python-3-i386
test-fedora-39-cpp
test-fedora-39-python-3
test-ubuntu-20.04-cpp
test-ubuntu-20.04-cpp-bundled
test-ubuntu-22.04-cpp
test-ubuntu-22.04-cpp-20
test-ubuntu-22.04-cpp-emscripten
test-ubuntu-22.04-cpp-no-threading
test-ubuntu-22.04-python-3
test-ubuntu-22.04-python-313-freethreading
test-ubuntu-24.04-cpp
test-ubuntu-24.04-cpp-bundled-offline
test-ubuntu-24.04-cpp-gcc-13-bundled
test-ubuntu-24.04-cpp-gcc-14
test-ubuntu-24.04-cpp-minimal-with-formats
test-ubuntu-24.04-cpp-thread-sanitizer
test-ubuntu-24.04-python-3
wheel-macos-monterey-cp310-cp310-amd64
wheel-macos-monterey-cp310-cp310-arm64
wheel-macos-monterey-cp311-cp311-amd64
wheel-macos-monterey-cp311-cp311-arm64
wheel-macos-monterey-cp312-cp312-amd64
wheel-macos-monterey-cp312-cp312-arm64
wheel-macos-monterey-cp313-cp313-amd64
wheel-macos-monterey-cp313-cp313-arm64
wheel-macos-monterey-cp313-cp313t-amd64
wheel-macos-monterey-cp313-cp313t-arm64
wheel-macos-monterey-cp39-cp39-amd64
wheel-macos-monterey-cp39-cp39-arm64
wheel-manylinux-2-28-cp310-cp310-amd64
wheel-manylinux-2-28-cp310-cp310-arm64
wheel-manylinux-2-28-cp311-cp311-amd64
wheel-manylinux-2-28-cp311-cp311-arm64
wheel-manylinux-2-28-cp312-cp312-amd64
wheel-manylinux-2-28-cp312-cp312-arm64
wheel-manylinux-2-28-cp313-cp313-amd64
wheel-manylinux-2-28-cp313-cp313-arm64
wheel-manylinux-2-28-cp313-cp313t-amd64
wheel-manylinux-2-28-cp313-cp313t-arm64
wheel-manylinux-2-28-cp39-cp39-amd64
wheel-manylinux-2-28-cp39-cp39-arm64
wheel-manylinux-2014-cp310-cp310-amd64
wheel-manylinux-2014-cp310-cp310-arm64
wheel-manylinux-2014-cp311-cp311-amd64
wheel-manylinux-2014-cp311-cp311-arm64
wheel-manylinux-2014-cp312-cp312-amd64
wheel-manylinux-2014-cp312-cp312-arm64
wheel-manylinux-2014-cp313-cp313-amd64
wheel-manylinux-2014-cp313-cp313-arm64
wheel-manylinux-2014-cp313-cp313t-amd64
wheel-manylinux-2014-cp313-cp313t-arm64
wheel-manylinux-2014-cp39-cp39-amd64
wheel-manylinux-2014-cp39-cp39-arm64
wheel-windows-cp310-cp310-amd64
wheel-windows-cp311-cp311-amd64
wheel-windows-cp312-cp312-amd64
wheel-windows-cp313-cp313-amd64
wheel-windows-cp313-cp313t-amd64
wheel-windows-cp39-cp39-amd64

[pitrou]

@github-actions crossbow submit -g linux -g r

[github-actions]

Revision: 318b69a

Submitted crossbow builds: ursacomputing/crossbow @ actions-e3ccd41a98

Task	Status
almalinux-8-amd64
almalinux-8-arm64
almalinux-9-amd64
almalinux-9-arm64
amazon-linux-2023-amd64
amazon-linux-2023-arm64
centos-7-amd64
centos-8-stream-amd64
centos-8-stream-arm64
centos-9-stream-amd64
centos-9-stream-arm64
debian-bookworm-amd64
debian-bookworm-arm64
debian-trixie-amd64
debian-trixie-arm64
r-binary-packages
r-recheck-most
test-r-arrow-backwards-compatibility
test-r-clang-sanitizer
test-r-depsource-bundled
test-r-depsource-system
test-r-dev-duckdb
test-r-devdocs
test-r-extra-packages
test-r-gcc-11
test-r-gcc-12
test-r-install-local
test-r-install-local-minsizerel
test-r-linux-as-cran
test-r-linux-rchk
test-r-linux-valgrind
test-r-macos-as-cran
test-r-minimal-build
test-r-offline-maximal
test-r-offline-minimal
test-r-rhub-debian-gcc-devel-lto-latest
test-r-rhub-debian-gcc-release-custom-ccache
test-r-rhub-ubuntu-release-latest
test-r-rocker-r-ver-latest
test-r-rstudio-r-base-4.1-opensuse155
test-r-rstudio-r-base-4.2-focal
test-r-ubuntu-22.04
test-r-versions
test-ubuntu-r-sanitizer
ubuntu-focal-amd64
ubuntu-focal-arm64
ubuntu-jammy-amd64
ubuntu-jammy-arm64
ubuntu-noble-amd64
ubuntu-noble-arm64

[pitrou]

So, it seems two main issues may be blocking this:

1. The AWS SDK fails to build ("Could not determine support for atomic operations")
2. CentOS 8 and Almalinux 8 do not have a C++20 compliant C++ stdlib (by default)

Edit: a couple R builds also seem to have a non-C++20 compliant stdlib.

@kou What is our policy for Almalinux and CentOS support?

[kou]

We can use gcc-toolset-{9,10,11,12,13,14} on AlmaLinux 8 and CentOS Stream 8 if we needed. For example, AlmaLinux 9 uses gcc-toolset-12:

arrow/dev/tasks/linux-packages/apache-arrow/yum/almalinux-9/Dockerfile

Line 21 in 16c7f1a

ENV SCL=gcc-toolset-12

arrow/dev/tasks/linux-packages/apache-arrow/yum/almalinux-9/Dockerfile

Line 29 in 16c7f1a

${SCL} \

[pitrou]

I see, thanks. So there are probably no insurmountable issues against switching to C++20. Of course, this will have to be discussed on the ML at some point (and there's no urgency).

[kou]

this will have to be discussed on the ML at some point

Right.

FYI: There is a related issue: #44792