markus@x4 ~ % c++filt _ZSt10__fill_n_aIPimiEN9__gnu_cxx11__enable_ifIXsr11__is_scalarIT1_EE7__valueET_E6__typeES4_T0_RKS3_ _ZSt10__fill_n_aIPimiEN9__gnu_cxx11__enable_ifIXsr11__is_scalarIT1_EE7__valueET_E6__typeES4_T0_RKS3_ markus@x4 ~ % c++filt _ZSt8__fill_aIPmiEN9__gnu_cxx11__enable_ifIXsr11__is_scalarIT0_EE7__valueEvE6__typeET_S6_RKS3_ _ZSt8__fill_aIPmiEN9__gnu_cxx11__enable_ifIXsr11__is_scalarIT0_EE7__valueEvE6__typeET_S6_RKS3_
__gnu_cxx::__enable_if<__is_scalar<int>::__value, int*>::__type std::__fill_n_a<int*, unsigned long, int>(int*, unsigned long, int const&) and __gnu_cxx::__enable_if<__is_scalar<int>::__value, void>::__type std::__fill_a<unsigned long*, int>(unsigned long*, unsigned long*, int const&) would be the correct answer.