https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96830
Bug ID: 96830 Summary: GCC does not complain template-head containing requires clause Product: gcc Version: 10.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: p.hyundeok76 at gmail dot com Target Milestone: --- Created attachment 49145 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49145&action=edit output of g++-10 -v -save-temps -std=c++2a test.cpp Summary When the member of a class template containing requires clause is defined outside the class, the code compiles although the definition does not specify the requires clause. Consider the code snippet below: template<typename Container> requires std::integral<typename Container::value_type> class Foo { public: void func(); }; template<typename Container> void Foo<Container>::func() {} As shown above, the definition of Foo<T>::func does not contain requires clause. But it compiles without an error. When compiled with clang, it complains. - version of GCC (tested on two machines) 1. Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/9/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:hsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 9.3.0-10ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-9/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,gm2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-9 --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-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 --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,hsa --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 9.3.0 (Ubuntu 9.3.0-10ubuntu2) 2. Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --with-isl --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-install-libiberty --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-libunwind-exceptions --disable-werror gdc_include_dir=/usr/include/dlang/gdc Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.2.0 (GCC) - system (output of uname -a excluding dates) 1. 4.4.0-18362-Microsoft #836-Microsoft x86_64 x86_64 x86_64 GNU/Linux 2. Linux arch 5.8.3-arch1-1 x86_64 GNU/Linux - options used for compilation -std=c++2a - command line that triggers the bug g++ -std=c++2a test.cpp - compiler output Nothing - preprocessed file (generated on the first system) test.ii