pub fn peer_cred(socket: &UnixStream) -> Result<UCred>Available on non-Hermit and (Unix) and not ((WebAssembly and non-WASI, or Fortanix and SGX)) and (Android or Linux or DragonFly BSD or FreeBSD or NetBSD or OpenBSD or QNX Neutrino or Apple or Cygwin) and (Linux or Android or Cygwin) only.