https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89991
--- Comment #28 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to kargl from comment #21) > Created attachment 46102 [details] > fix g++ problem with sqrt(z) where z is complex and imag(z) = -0 This one assumes copysign is valid for arguments of type _Tp, which is only true for float, double and long double. std::pow might make sense for complex integers, but seems to be already broken, so this doesn't make it any worse there. To preserve support for user-defined numeric types (and decimal floats?) we could add an overloaded helper for copysign which retains the `__x < _Tp()` check for the generic overload and uses copysign for floating point types. (In reply to kargl from comment #23) > Created attachment 46105 [details] > fix g++ problem with pow(z,0.5) where imag(z) = -0. > > This patch has only been tested with the original test provided by the > reporter. This one makes me a little uncomfortable with the use of abs, but we already use that elsewhere (and inconsistently qualify it as std::abs). Again, this doesn't seem to make anything worse w.r.t our support for types other than float, double and long double.
