https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99865
Bug ID: 99865 Summary: std::filesystem namespace identifiers pollute global namespace Product: gcc Version: 10.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: zoid at riseup dot net Target Milestone: --- At least two free functions from the std::filesystem namespace resolve without being scope-resolved. The two I found were std::filesystem::create_directory and std::filesystem::remove_all. There might be more. I am uncertain if this is a problem in the library implementation or the compiler itself. Minimal Reproducible Example: #include <filesystem> struct TempDir { std::filesystem::path const path; TempDir(std::filesystem::path const& p) : path(p) { // std::filesystem::create_directory(p); // <-- expected if (!create_directory(p)) { // <- compiles throw 0; } } ~TempDir() { // std::filesystem::remove_all(path); // <-- expected remove_all(path); // <- compiles } }; int main() { // create_directory("bar"); // <- rejected (correctly) TempDir("foo"); } Compile with: g++ -Wall -Wextra -pedantic -std=c++17 mre.cpp Produces zero diagnostics. Compiles binary a.out. My expectation would have been that the compiler rejected the lines marked with "compiles". As it does when these identifiers appear directly in main. Tested with g++ 10.2.1 under both debian and fedora. Output of g++ -v: Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 10.2.1-6' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-10 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-10-Km9U7s/gcc-10-10.2.1/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-Km9U7s/gcc-10-10.2.1/debian/tmp-gcn/usr,hsa --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-mutex Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.2.1 20210110 (Debian 10.2.1-6)