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

c_glib/meson.build

@@ -20,7 +20,7 @@
 project('arrow-glib', 'c', 'cpp',
         default_options: [
           'c_std=c99',
-          'cpp_std=c++17',
+          'cpp_std=c++20',
         ],
         license: 'Apache-2.0',
         # Debian:

ci/appveyor-cpp-build.bat

@@ -93,7 +93,7 @@ cmake -G "%GENERATOR%" %ARROW_CMAKE_ARGS% ^
       -DARROW_WITH_ZSTD=ON ^
       -DCMAKE_BUILD_TYPE="Release" ^
       -DCMAKE_CXX_FLAGS_RELEASE="/MD /Od /UNDEBUG" ^
-      -DCMAKE_CXX_STANDARD=17 ^
+      -DCMAKE_CXX_STANDARD=20 ^
       -DCMAKE_INSTALL_PREFIX=%CONDA_PREFIX%\Library ^
       -DCMAKE_UNITY_BUILD=ON ^
       -DCMAKE_VERBOSE_MAKEFILE=OFF ^

ci/scripts/cpp_build.sh

@@ -125,7 +125,7 @@ if [ "${ARROW_EMSCRIPTEN:-OFF}" = "ON" ]; then
     -DCMAKE_VERBOSE_MAKEFILE=${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} \
@@ -216,7 +216,7 @@ 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} \

cpp/CMakeLists.txt

@@ -553,10 +553,10 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${ARROW_CXXFLAGS}")
 # C++ specific flags.
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CXX_COMMON_FLAGS} ${ARROW_CXXFLAGS}")
 
-# Remove --std=c++17 to avoid errors from C compilers
-string(REPLACE "-std=c++17" "" CMAKE_C_FLAGS ${CMAKE_C_FLAGS})
+# Remove -std=c++20 to avoid errors from C compilers
+string(REPLACE "-std=c++20" "" CMAKE_C_FLAGS ${CMAKE_C_FLAGS})
 
-# Add C++-only flags, like -std=c++17
+# Add C++-only flags, like -std=c++20
 set(CMAKE_CXX_FLAGS "${CXX_ONLY_FLAGS} ${CMAKE_CXX_FLAGS}")
 
 # ASAN / TSAN / UBSAN

cpp/cmake_modules/GandivaAddBitcode.cmake

@@ -17,7 +17,7 @@
 
 # Create bitcode for the given source file.
 function(gandiva_add_bitcode SOURCE)
-  set(CLANG_OPTIONS -std=c++17)
+  set(CLANG_OPTIONS -std=c++20)
   if(MSVC)
     # "19.20" means that it's compatible with Visual Studio 16 2019.
     # We can update this to "19.30" when we dropped support for Visual

cpp/cmake_modules/SetupCxxFlags.cmake

@@ -137,12 +137,12 @@ endif()
 
 # This ensures that things like c++17 get passed correctly
 if(NOT DEFINED CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD 17)
-elseif(${CMAKE_CXX_STANDARD} VERSION_LESS 17)
-  message(FATAL_ERROR "Cannot set a CMAKE_CXX_STANDARD smaller than 17")
+  set(CMAKE_CXX_STANDARD 20)
+elseif(${CMAKE_CXX_STANDARD} VERSION_LESS 20)
+  message(FATAL_ERROR "Cannot set a CMAKE_CXX_STANDARD smaller than 20")
 endif()
 
-# We require a C++17 compliant compiler
+# We require a C++20 compliant compiler
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # ARROW-6848: Do not use GNU (or other CXX) extensions

cpp/examples/minimal_build/CMakeLists.txt

@@ -24,10 +24,10 @@ option(ARROW_LINK_SHARED "Link to the Arrow shared library" ON)
 find_package(Arrow REQUIRED)
 
 if(NOT DEFINED CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD 17)
+  set(CMAKE_CXX_STANDARD 20)
 endif()
 
-# We require a C++17 compliant compiler
+# We require a C++20 compliant compiler
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 if(NOT CMAKE_BUILD_TYPE)

cpp/examples/minimal_build/run_static.sh

@@ -86,7 +86,7 @@ echo
 
 rm -rf $EXAMPLE_BUILD_DIR
 mkdir -p $EXAMPLE_BUILD_DIR
-${CXX:-c++} -std=c++17 \
+${CXX:-c++} -std=c++20 \
   -o $EXAMPLE_BUILD_DIR/arrow-example \
   $EXAMPLE_DIR/example.cc \
   $(PKG_CONFIG_PATH=$ARROW_BUILD_DIR/lib/pkgconfig \

cpp/examples/parquet/parquet_arrow/CMakeLists.txt

@@ -28,10 +28,10 @@ option(PARQUET_LINK_SHARED "Link to the Parquet shared library" ON)
 
 # This ensures that things like -std=gnu++... get passed correctly
 if(NOT DEFINED CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD 17)
+  set(CMAKE_CXX_STANDARD 20)
 endif()
 
-# We require a C++17 compliant compiler
+# We require a C++20 compliant compiler
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # Look for installed packages the system

cpp/examples/tutorial_examples/CMakeLists.txt

@@ -21,7 +21,7 @@ project(ArrowTutorialExamples)
 
 find_package(ArrowDataset)
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror -Wall -Wextra")
 
 set(CMAKE_BUILD_TYPE Release)

cpp/src/arrow/util/string.h

@@ -54,14 +54,12 @@ namespace internal {
 
 /// Like std::string_view::starts_with in C++20
 inline bool StartsWith(std::string_view s, std::string_view prefix) {
-  return s.length() >= prefix.length() &&
-         (s.empty() || s.substr(0, prefix.length()) == prefix);
+  return s.starts_with(prefix);
 }
 
 /// Like std::string_view::ends_with in C++20
 inline bool EndsWith(std::string_view s, std::string_view suffix) {
-  return s.length() >= suffix.length() &&
-         (s.empty() || s.substr(s.length() - suffix.length()) == suffix);
+  return s.ends_with(suffix);
 }
 
 /// \brief Split a string with a delimiter

dev/release/verify-apt.sh

@@ -165,7 +165,7 @@ pushd build/minimal_build
 cmake .
 make -j$(nproc)
 ./arrow-example
-c++ -o arrow-example example.cc $(pkg-config --cflags --libs arrow) -std=c++17
+c++ -o arrow-example example.cc $(pkg-config --cflags --libs arrow) -std=c++20
 ./arrow-example
 popd
 echo "::endgroup::"

dev/release/verify-yum.sh

@@ -228,7 +228,7 @@ pushd build/minimal_build
 ${cmake_command} .
 make -j$(nproc)
 ./arrow-example
-c++ -o arrow-example example.cc $(pkg-config --cflags --libs arrow) -std=c++17
+c++ -o arrow-example example.cc $(pkg-config --cflags --libs arrow) -std=c++20
 ./arrow-example
 popd
 echo "::endgroup::"

dev/tasks/conda-recipes/arrow-cpp/build-arrow.bat

@@ -52,7 +52,7 @@ cmake -G "Ninja" ^
       -DBUILD_SHARED_LIBS=ON ^
       -DBoost_NO_BOOST_CMAKE=ON ^
       -DCMAKE_BUILD_TYPE=release ^
-      -DCMAKE_CXX_STANDARD=17 ^
+      -DCMAKE_CXX_STANDARD=20 ^
       -DCMAKE_INSTALL_PREFIX="%LIBRARY_PREFIX%" ^
       -DCMAKE_UNITY_BUILD=ON ^
       -DLLVM_TOOLS_BINARY_DIR="%LIBRARY_BIN%" ^

dev/tasks/conda-recipes/arrow-cpp/build-arrow.sh

@@ -107,7 +107,7 @@ cmake -GNinja \
     -DARROW_WITH_ZSTD=ON \
     -DBUILD_SHARED_LIBS=ON \
     -DCMAKE_BUILD_TYPE=release \
-    -DCMAKE_CXX_STANDARD=17 \
+    -DCMAKE_CXX_STANDARD=20 \
     -DCMAKE_INSTALL_LIBDIR=lib \
     -DCMAKE_INSTALL_PREFIX=$PREFIX \
     -DLLVM_TOOLS_BINARY_DIR=$PREFIX/bin \

dev/tasks/homebrew-formulae/apache-arrow.rb

@@ -110,7 +110,7 @@ def install
         return 0;
       }
     EOS
-    system ENV.cxx, "test.cpp", "-std=c++17", "-I#{include}", "-L#{lib}", "-larrow", "-o", "test"
+    system ENV.cxx, "test.cpp", "-std=c++20", "-I#{include}", "-L#{lib}", "-larrow", "-o", "test"
     system "./test"
   end
 end

docs/source/java/cdata.rst

@@ -154,7 +154,7 @@ without writing JNI bindings ourselves.
                    include = {
                            "CDataCppBridge.h"
                    },
-                   compiler = {"cpp17"},
+                   compiler = {"cpp20"},
                    linkpath = {"/arrow/cpp/build/debug/"},
                    link = {"arrow"}
            )
@@ -436,7 +436,7 @@ CMakeLists.txt definition file:
    find_package(Arrow REQUIRED)
    message(STATUS "Arrow version: ${ARROW_VERSION}")
    include_directories(${JNI_INCLUDE_DIRS})
-   set(CMAKE_CXX_STANDARD 17)
+   set(CMAKE_CXX_STANDARD 20)
    add_executable(${PROJECT_NAME} main.cpp)
    target_link_libraries(cdatacpptojava PRIVATE Arrow::arrow_shared)
    target_link_libraries(cdatacpptojava PRIVATE ${JNI_LIBRARIES})

docs/source/python/integration/extending.rst

@@ -441,7 +441,7 @@ To build this module, you will need a slightly customized ``setup.py`` file
         ext.library_dirs.extend(pa.get_library_dirs())
 
         if os.name == 'posix':
-            ext.extra_compile_args.append('-std=c++17')
+            ext.extra_compile_args.append('-std=c++20')
 
     setup(ext_modules=ext_modules)
 

matlab/CMakeLists.txt

@@ -98,7 +98,7 @@ function(build_arrow)
 
 endfunction()
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 
 set(MLARROW_VERSION "20.0.0-SNAPSHOT")
 string(REGEX MATCH "^[0-9]+\\.[0-9]+\\.[0-9]+" MLARROW_BASE_VERSION "${MLARROW_VERSION}")

python/CMakeLists.txt

@@ -230,7 +230,7 @@ endif()
 # For any C code, use the same flags.
 set(CMAKE_C_FLAGS "${CMAKE_CXX_FLAGS}")
 
-# Add C++-only flags, like -std=c++17
+# Add C++-only flags, like -std=c++20
 set(CMAKE_CXX_FLAGS "${CXX_ONLY_FLAGS} ${CMAKE_CXX_FLAGS}")
 
 message(STATUS "CMAKE_C_FLAGS: ${CMAKE_C_FLAGS}")

python/pyarrow/tests/test_cython.py

@@ -28,9 +28,9 @@
 here = os.path.dirname(os.path.abspath(__file__))
 test_ld_path = os.environ.get('PYARROW_TEST_LD_PATH', '')
 if os.name == 'posix':
-    compiler_opts = ['-std=c++17']
+    compiler_opts = ['-std=c++20']
 elif os.name == 'nt':
-    compiler_opts = ['-D_ENABLE_EXTENDED_ALIGNED_STORAGE', '/std:c++17']
+    compiler_opts = ['-D_ENABLE_EXTENDED_ALIGNED_STORAGE', '/std:c++20']
 else:
     compiler_opts = []