https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55993
splinterofchaos at gmail dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |splinterofchaos at gmail dot com --- Comment #11 from splinterofchaos at gmail dot com --- I still get an error with 4.9 when using one of the less reduced cases, although not when using the test cases in that patch. #include <tuple> struct A {}; constexpr auto t = std::get<0>( std::make_tuple( A(), A() ) ); $ g++ test.cpp -std=c++14 -Wall -Wextra; and ./a.out; echo $status test.cpp:3:61: in constexpr expansion of ‘std::get<0ul, {A, A}>((* & std::make_tuple(_Elements&& ...) [with _Elements = {A, A}]((* & A()))))’ /usr/include/c++/4.9/tuple:774:44: in constexpr expansion of ‘std::get<0ul, {A, A}>((* & __t))’ /usr/include/c++/4.9/tuple:757:40: in constexpr expansion of ‘std::__get_helper<0ul, A, {A}>((*(std::_Tuple_impl<0ul, A, A>*)(& __t)))’ /usr/include/c++/4.9/tuple:744:60: in constexpr expansion of ‘std::_Tuple_impl<_Idx, _Head, _Tail ...>::_M_head<0ul, A, {A}>((* & __t))’ test.cpp:3:61: error: ‘(std::_Head_base<0ul, A, true>*)(& std::tuple<A, A>())’ is not a constant expression constexpr auto t = std::get<0>( std::make_tuple( A(), A() ) ); $ g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.9.1-16ubuntu6' --with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.9 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.9.1 (Ubuntu 4.9.1-16ubuntu6)