https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96286
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2021-07-15 Ever confirmed|0 |1 --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- This is a major pain the backside for trying to give good diagnostics for std::get<T>(tuple<Types...>&). I want to stop with a "clear" static assertion like: In file included from /home/jwakely/src/gcc/gcc/libstdc++-v3/testsuite/20_util/tuple/element_access/101427.cc:3: /home/jwakely/gcc/12/include/c++/12.0.0/tuple: In instantiation of 'constexpr std::size_t std::__find_uniq_type_in_pack() [with _Tp = long int; _Types = {float, int, int}; std::size_t = long unsigned int]': /home/jwakely/gcc/12/include/c++/12.0.0/tuple:1452:63: required from 'constexpr _Tp& std::get(std::tuple<_UTypes ...>&) [with _Tp = long int; _Types = {float, int, int}]' /home/jwakely/src/gcc/gcc/libstdc++-v3/testsuite/20_util/tuple/element_access/101427.cc:7:22: required from here /home/jwakely/gcc/12/include/c++/12.0.0/tuple:1441:27: error: static assertion failed: the type T in std::get<T> must occur exactly once in the tuple 1441 | static_assert(__idx >= 0, | ~~~~~~^~~~ But G++ insists on continuing past that point, returning an out-of-range index which causes 200 lines of errors because std::get<SIZE_MAX>(t) is invalid. I know it's invalid, that's why I made the static assertion fail. Just stop. I now have to jump through ridiculous hoops to add additional code to munge the invalid value into some other value to stop the 200 lines of noise.