GH-45885: [C++] Require C++20 (#48414)

### Rationale for this change

We decided to migrate Arrow C++ to C++20 in this discussion: https://lists.apache.org/thread/48zlj0dn2y0f53y2k37qsr90y781wfnj

### What changes are included in this PR?

1. Build configuration updates (CMake files etc.) to build with C++20 instead of C++17

2. C++-level fixes to ensure compilation succeeds:

    * Workarounds for deprecation of atomic access on `std::shared_ptr<T>` (the replacement `std::atomic<std::shared_ptr<T>>` is unfortunately not supported in all standard library implementations)
    * Workaround for [Abseil ABI issues](abseil/abseil-cpp#1624)
    * Trivial update to `arrow/util/string.h` to call a C++20 API (to validate that C++20 is actually enabled)

3. CI configuration updates to get enough C++20 support on the various platforms:

    * Bump default clang and LLVM versions to 18
    * Use AlmaLinux 10 for release verification (AlmaLinux 8 is still tested on other CI builds)

### Are these changes tested?

Yes.

### Are there any user-facing changes?

Yes, Arrow C++ will now require a C++20-compliant compiler.

* GitHub Issue: #45885

Authored-by: Antoine Pitrou <[email protected]>
Signed-off-by: Antoine Pitrou <[email protected]>

Author: pitrou

.env

@@ -57,7 +57,7 @@ FEDORA=42
 UBUNTU=22.04
 
 # Default versions for various dependencies
-CLANG_TOOLS=14
+CLANG_TOOLS=18
 CMAKE=3.26.0
 CUDA=11.7.1
 DASK=latest

.github/workflows/cpp.yml

@@ -81,24 +81,24 @@ jobs:
       matrix:
         include:
           - arch: amd64
-            clang-tools: 14
+            clang-tools: 18
             image: conda-cpp
-            llvm: 14
+            llvm: 18
             runs-on: ubuntu-latest
             simd-level: AVX2
             title: AMD64 Conda C++ AVX2
             ubuntu: 22.04
           - arch: amd64
-            clang-tools: 14
+            clang-tools: 18
             image: ubuntu-cpp-sanitizer
-            llvm: 14
+            llvm: 18
             runs-on: ubuntu-latest
             title: AMD64 Ubuntu 24.04 C++ ASAN UBSAN
             ubuntu: 24.04
           - arch: arm64v8
-            clang-tools: 14
+            clang-tools: 18
             image: ubuntu-cpp
-            llvm: 14
+            llvm: 18
             runs-on: ubuntu-24.04-arm
             title: ARM64 Ubuntu 22.04 C++
             ubuntu: 22.04

.github/workflows/cpp_extra.yml

@@ -347,7 +347,6 @@ jobs:
       ARROW_DEPENDENCY_SOURCE: VCPKG
       ARROW_FLIGHT_SQL_ODBC: ON
       ARROW_SIMD_LEVEL: AVX2
-      CMAKE_CXX_STANDARD: "17"
       CMAKE_GENERATOR: Ninja
       CMAKE_INSTALL_PREFIX: /usr
       VCPKG_BINARY_SOURCES: 'clear;nuget,GitHub,readwrite'

.github/workflows/cpp_windows.yml

@@ -63,7 +63,7 @@ jobs:
       ARROW_WITH_ZLIB: ON
       ARROW_WITH_ZSTD: ON
       BOOST_SOURCE: BUNDLED
-      CMAKE_CXX_STANDARD: "17"
+      CMAKE_CXX_STANDARD: "20"
       CMAKE_GENERATOR: Ninja
       CMAKE_INSTALL_PREFIX: /usr
       CMAKE_UNITY_BUILD: ON

.github/workflows/r.yml

@@ -229,12 +229,13 @@ jobs:
           # static library. The R is not used here but R 4.1 was the last R to use
           # Rtools40.
           r-version: "4.1"
-          rtools-version: 40
+          rtools-version: ${{ matrix.config.rtools }}
           Ncpus: 2
       - name: Build Arrow C++
         shell: bash
         env:
           MINGW_ARCH: ${{ matrix.config.arch }}
+          RTOOLS_VERSION: ${{ matrix.config.rtools }}
         run: ci/scripts/r_windows_build.sh
       - name: Rename libarrow.zip
         # So that they're unique when multiple are downloaded in the next step

.github/workflows/ruby.yml

@@ -349,7 +349,7 @@ jobs:
       ARROW_WITH_SNAPPY: ON
       ARROW_WITH_ZLIB: ON
       ARROW_WITH_ZSTD: ON
-      CMAKE_CXX_STANDARD: "17"
+      CMAKE_CXX_STANDARD: "20"
       CMAKE_GENERATOR: Ninja
       CMAKE_INSTALL_PREFIX: "${{ github.workspace }}/dist"
       VCPKG_BINARY_SOURCES: 'clear;nuget,GitHub,readwrite'

c_glib/meson.build

@@ -21,7 +21,7 @@ project(
     'arrow-glib',
     'c',
     'cpp',
-    default_options: ['c_std=c99', 'cpp_std=c++17'],
+    default_options: ['c_std=c99', 'cpp_std=c++20'],
     license: 'Apache-2.0',
     # Debian:
     #   https://packages.debian.org/search?keywords=meson

ci/docker/almalinux-10-verify-rc.dockerfile

@@ -0,0 +1,24 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+ARG arch=amd64
+FROM ${arch}/almalinux:10
+
+COPY dev/release/setup-rhel-rebuilds.sh /
+RUN /setup-rhel-rebuilds.sh && \
+    rm /setup-rhel-rebuilds.sh && \
+    dnf -y clean all

ci/docker/debian-experimental-cpp.dockerfile

@@ -59,6 +59,7 @@ RUN if [ -n "${gcc}" ]; then \
         libldap-dev \
         liblz4-dev \
         libnghttp2-dev \
+        libopentelemetry-proto-dev \
         libprotobuf-dev \
         libprotoc-dev \
         libpsl-dev \
@@ -88,6 +89,7 @@ RUN if [ -n "${gcc}" ]; then \
         rapidjson-dev \
         rsync \
         tzdata \
+        tzdata-legacy \
         zlib1g-dev && \
     apt-get install -y -q --no-install-recommends -t experimental \
         clang${llvm_package_suffix} \

ci/scripts/cpp_build.sh

@@ -168,7 +168,7 @@ elif [ "${ARROW_EMSCRIPTEN:-OFF}" = "ON" ]; then
     -DCMAKE_VERBOSE_MAKEFILE=${CMAKE_VERBOSE_MAKEFILE:-OFF} \
     -DCMAKE_C_FLAGS="${CFLAGS:-}" \
     -DCMAKE_CXX_FLAGS="${CXXFLAGS:-}" \
-    -DCMAKE_CXX_STANDARD="${CMAKE_CXX_STANDARD:-17}" \
+    -DCMAKE_CXX_STANDARD="${CMAKE_CXX_STANDARD:-20}" \
     -DCMAKE_INSTALL_LIBDIR=${CMAKE_INSTALL_LIBDIR:-lib} \
     -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX:-${ARROW_HOME}} \
     -DCMAKE_UNITY_BUILD=${CMAKE_UNITY_BUILD:-OFF} \
@@ -260,7 +260,7 @@ else
     -DCMAKE_VERBOSE_MAKEFILE=${CMAKE_VERBOSE_MAKEFILE:-OFF} \
     -DCMAKE_C_FLAGS="${CFLAGS:-}" \
     -DCMAKE_CXX_FLAGS="${CXXFLAGS:-}" \
-    -DCMAKE_CXX_STANDARD="${CMAKE_CXX_STANDARD:-17}" \
+    -DCMAKE_CXX_STANDARD="${CMAKE_CXX_STANDARD:-20}" \
     -DCMAKE_INSTALL_LIBDIR=${CMAKE_INSTALL_LIBDIR:-lib} \
     -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX:-${ARROW_HOME}} \
     -DCMAKE_UNITY_BUILD=${CMAKE_UNITY_BUILD:-OFF} \