https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102338
--- Comment #4 from Jerguš Suja <jergussuja at gmail dot com> --- gcc version 9.3.0 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 Code that trigger compilation failed: struct S { template<typename T> static auto f(T && t) noexcept { return true; } template<typename T, typename... Ts> static auto f(T && t, Ts && ... ts) noexcept(noexcept(f(ts...))) { return f(ts...); } }; int main() { S::f(true, 0, 5u); return 0; } Compiler error: bug.cpp: In instantiation of ‘static auto S::f(T&&, Ts&& ...) [with T = bool; Ts = {int, unsigned int}]’: bug.cpp:16:21: required from here bug.cpp:9:60: error: no matching function for call to ‘S::f(int&, unsigned int&)’ 9 | static auto f(T && t, Ts && ... ts) noexcept(noexcept(f(ts...))) { | ~^~~~~~~ bug.cpp:4:17: note: candidate: ‘template<class T> static auto S::f(T&&)’ 4 | static auto f(T && t) noexcept { | ^ bug.cpp:4:17: note: template argument deduction/substitution failed: bug.cpp:9:60: note: candidate expects 1 argument, 2 provided 9 | static auto f(T && t, Ts && ... ts) noexcept(noexcept(f(ts...))) { | ~^~~~~~~ GCC version 7.5 compile this, but version 8 and more does not. If I declare function 'f' in scope of class or struct, it should be visible everywhere inside class/struct scope. Also in noexcept specifier (it should not matter if it is recursive call). MSVC v19.28 and Clang 12.0.1 accept this and compile this code.