https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110646
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to John David Anglin from comment #0) > libstdc++ provides std::stoi in basic_string.h when _GLIBCXX_USE_C99_STDLIB > is 1. However, hpux11.11 lacks all the routines needed when > _GLIBCXX_USE_C99_STDLIB is 1. But it does have strtol, atol, atoi, strtoul, > strtod and atof. strtoll and strtoull are not needed on hppa64 as long long > and long are equivalent. So it seems the string conversion routines could > be provided in basic_string.h for this target. Yes, those checks could be more granular. I'll split out the checks needed for std::stoi etc.