https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68383
--- Comment #1 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- @fi...@zefix.tv Ian asks: »Was the symbol _ZSt7forwardIRKZN5Write14DataMapGrammarISt20back_insert_iteratorISsEEC4EvEUlRT_E_EOS5_RNSt16remove_referenceIS5_E4typeE generated by g++ or clang? That is, is it supposed to demangle? If so, do you have the source code?»