Man pages matching name std::experimental::filesystem::filesystem_error in section 3cxx:

std::experimental::filesystem::filesystem_error.3cxx.en	debian 11 / libstdc++-10-doc
std::experimental::filesystem::filesystem_error.3cxx.en	debian 12 / libstdc++-11-doc
std::experimental::filesystem::filesystem_error.3cxx.en	debian 12 / libstdc++-12-doc