Utilize std::filesystem

CMakeLists.txt

@@ -139,7 +139,7 @@ endif ()
 # -------------------------------------------------------------------------------- #
 
 # -------------------------------------------------------------------------------- #
-# Executables
+# Set up for building executables
 # -------------------------------------------------------------------------------- #
 
 # Requirements for GCC
@@ -169,12 +169,8 @@ find_package(Threads REQUIRED)
 
 
 # ---------- filesystem ---------- #
-include(include_cxx_filesystem_library)
-include_cxx_filesystem_library()
-
-# Xcode 11 Beta Release Notes
-# Clang now supports the C++17 <filesystem> library for iOS 13, macOS 10.15, watchOS 6, and tvOS 13. (50988273)
-# https://developer.apple.com/documentation/xcode_release_notes/xcode_11_beta_release_notes?language=objc
+include(check_cxx_filesystem_library)
+check_cxx_filesystem_library()
 
 
 # ---------- UMap ---------- #
@@ -198,7 +194,7 @@ set(Boost_NO_BOOST_CMAKE ON)
 find_package(Boost 1.64 QUIET)
 if (NOT Boost_FOUND)
     FetchContent_Declare(Boost
-            URL https://boostorg.jfrog.io/artifactory/main/release/1.78.0/source/boost_1_78_0.tar.bz2)
+            URL https://boostorg.jfrog.io/artifactory/main/release/1.83.0/source/boost_1_83_0.tar.bz2)
     FetchContent_GetProperties(Boost)
     if (NOT Boost_POPULATED)
         FetchContent_Populate(Boost)
@@ -258,13 +254,11 @@ function(common_setup_for_metall_executable name)
     # --------------------
 
     # ----- CXX17 Filesystem Lib----- #
-    # include_cxx_filesystem_library module must be executed first
-    if (FOUND_CXX17_FILESYSTEM_LIB)
-        if (REQUIRE_LIB_STDCXX_FS)
+    # GNU compilers prior to 9.1 requires linking with stdc++fs
+    if (("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU") OR ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU"))
+        if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.1)
             target_link_libraries(${name} PRIVATE stdc++fs)
         endif ()
-    elseif ()
-        target_compile_definitions(${name} PRIVATE "METALL_DISABLE_CXX17_FILESYSTEM_LIB")
     endif ()
     # --------------------
 

bench/bfs/run_bfs_bench_metall.cpp

@@ -29,7 +29,7 @@ int main(int argc, char *argv[]) {
     // metall::logger::set_log_level(metall::logger::level::verbose);
 
     metall::manager manager(metall::open_read_only,
-                            option.graph_file_name_list[0].c_str());
+                            option.graph_file_name_list[0]);
     auto adj_list =
         manager.find<adjacency_list_type>(option.graph_key_name.c_str()).first;
 

bench/bfs/run_bfs_bench_metall_multiple.cpp

@@ -33,7 +33,7 @@ int main(int argc, char *argv[]) {
     std::vector<metall::manager *> managers;
     for (const auto &file_name : option.graph_file_name_list) {
       managers.emplace_back(
-          new metall::manager(metall::open_read_only, file_name.c_str()));
+          new metall::manager(metall::open_read_only, file_name));
     }
 
     auto adj_list = adjacency_list_type(option.graph_key_name, managers.begin(),

bench/simple_alloc/run_simple_allocation_bench_metall.cpp

@@ -13,7 +13,7 @@
 int main(int argc, char *argv[]) {
   const auto option = simple_alloc_bench::parse_option(argc, argv);
   {
-    metall::manager manager(metall::create_only, option.datastore_path.c_str());
+    metall::manager manager(metall::create_only, option.datastore_path);
     simple_alloc_bench::run_bench(option, manager.get_allocator<std::byte>());
   }
   metall::manager::remove(option.datastore_path.c_str());

cmake/check_cxx_filesystem_library.cmake

@@ -0,0 +1,25 @@
+# Checks if the C++17 <filesystem> library is available.
+function(check_cxx_filesystem_library)
+
+    set(FOUND_CXX17_FILESYSTEM_LIB FALSE PARENT_SCOPE)
+    set(REQUIRE_LIB_STDCXX_FS FALSE PARENT_SCOPE)
+
+    # Check if C++17 <filesystem> header files are available
+    # If not, uses our own implementation.
+    include(CheckIncludeFileCXX)
+    CHECK_INCLUDE_FILE_CXX(filesystem FOUND_FILESYSTEM_HEADER)
+    if (NOT FOUND_FILESYSTEM_HEADER)
+        message(FATAL_ERROR "Cannot find the C++17 <filesystem> library.")
+    endif ()
+
+    if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")  # Clang or AppleClang
+        if (${CMAKE_HOST_SYSTEM_NAME} MATCHES "Darwin") # macOS
+            include(get_macos_version)
+            get_macos_version() # Get macOS version
+            message(VERBOSE "Detected macOS version ${MACOS_VERSION}")
+            if (MACOS_VERSION VERSION_LESS 10.15) # macOS < 10.15
+                message(FATAL_ERROR "macOS >= 10.15 is required to use the C++17 <filesystem> library.")
+            endif ()
+        endif ()
+    endif ()
+endfunction()

docs/readthedocs/basics/getting_started.md

@@ -69,22 +69,11 @@ g++ -std=c++17 your_program.cpp -lstdc++fs -I${BOOST_ROOT}/include -I${METALL_RO
 
 Clang (or Apple clang) could be used instead of GCC to build Metall.
 However, we haven't tested it intensively.
+To run on macOS, Metall requires macOS >= 10.15.
+
 Also, Boost C++ Libraries 1.69 or more may be required
 if one wants to build Metall with Clang + CUDA.
 
-**On macOS >= 10.15 or Linux**
-
 ```bash
-# Remove "-lstdc++fs" option
 clang++ -std=c++17 [tutorial_program.cpp] -I../../include -I${BOOST_ROOT}
-```
-
-**On macOS < 10.15**
-
-The C++17 <filesystem> library is not available on macOS < 10.15.
-One has to stop using C++17 <filesystem> library in Metall.
-If METALL_DISABLE_CXX17_FILESYSTEM_LIB macro is defined, Metall uses its own file system operation implementation.
-
-```bash
-clang++ -std=c++17 [tutorial_program.cpp] -I../../include -I${BOOST_ROOT} -DMETALL_DISABLE_CXX17_FILESYSTEM_LIB
-```
+```