Change uses of never type

15 files changed, 198 insertions, 196 deletions

diff --git a/library/std/src/sys/hermit/fs.rs b/library/std/src/sys/hermit/fs.rs
index fb6b4a8b54e..5b3f2fa4e82 100644
--- a/library/std/src/sys/hermit/fs.rs
+++ b/library/std/src/sys/hermit/fs.rs
@@ -50,55 +50,55 @@ pub struct DirBuilder {}
 
 impl FileAttr {
     pub fn size(&self) -> u64 {
-        match self.0 {}
+        self.0
     }
 
     pub fn perm(&self) -> FilePermissions {
-        match self.0 {}
+        self.0
     }
 
     pub fn file_type(&self) -> FileType {
-        match self.0 {}
+        self.0
     }
 
     pub fn modified(&self) -> io::Result<SystemTime> {
-        match self.0 {}
+        self.0
     }
 
     pub fn accessed(&self) -> io::Result<SystemTime> {
-        match self.0 {}
+        self.0
     }
 
     pub fn created(&self) -> io::Result<SystemTime> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for FileAttr {
     fn clone(&self) -> FileAttr {
-        match self.0 {}
+        self.0
     }
 }
 
 impl FilePermissions {
     pub fn readonly(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_readonly(&mut self, _readonly: bool) {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for FilePermissions {
     fn clone(&self) -> FilePermissions {
-        match self.0 {}
+        self.0
     }
 }
 
 impl PartialEq for FilePermissions {
     fn eq(&self, _other: &FilePermissions) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -106,27 +106,27 @@ impl Eq for FilePermissions {}
 
 impl fmt::Debug for FilePermissions {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
 impl FileType {
     pub fn is_dir(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_file(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_symlink(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for FileType {
     fn clone(&self) -> FileType {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -134,7 +134,7 @@ impl Copy for FileType {}
 
 impl PartialEq for FileType {
     fn eq(&self, _other: &FileType) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -142,19 +142,19 @@ impl Eq for FileType {}
 
 impl Hash for FileType {
     fn hash<H: Hasher>(&self, _h: &mut H) {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for FileType {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for ReadDir {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -162,25 +162,25 @@ impl Iterator for ReadDir {
     type Item = io::Result<DirEntry>;
 
     fn next(&mut self) -> Option<io::Result<DirEntry>> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl DirEntry {
     pub fn path(&self) -> PathBuf {
-        match self.0 {}
+        self.0
     }
 
     pub fn file_name(&self) -> OsString {
-        match self.0 {}
+        self.0
     }
 
     pub fn metadata(&self) -> io::Result<FileAttr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn file_type(&self) -> io::Result<FileType> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/hermit/net.rs b/library/std/src/sys/hermit/net.rs
index bdb7b81fdc0..5f8839157ea 100644
--- a/library/std/src/sys/hermit/net.rs
+++ b/library/std/src/sys/hermit/net.rs
@@ -415,14 +415,14 @@ pub struct LookupHost(!);
 
 impl LookupHost {
     pub fn port(&self) -> u16 {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Iterator for LookupHost {
     type Item = SocketAddr;
     fn next(&mut self) -> Option<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/hermit/os.rs b/library/std/src/sys/hermit/os.rs
index ab5e0ea0bc4..4487e9d636c 100644
--- a/library/std/src/sys/hermit/os.rs
+++ b/library/std/src/sys/hermit/os.rs
@@ -29,7 +29,7 @@ pub fn chdir(_: &path::Path) -> io::Result<()> {
     unsupported()
 }
 
-pub struct SplitPaths<'a>(&'a !);
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
 
 pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
     panic!("unsupported")
@@ -38,7 +38,7 @@ pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
 impl<'a> Iterator for SplitPaths<'a> {
     type Item = PathBuf;
     fn next(&mut self) -> Option<PathBuf> {
-        match *self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/sgx/net.rs b/library/std/src/sys/sgx/net.rs
index 9ddd17303db..5ccedece0f8 100644
--- a/library/std/src/sys/sgx/net.rs
+++ b/library/std/src/sys/sgx/net.rs
@@ -318,129 +318,129 @@ impl UdpSocket {
     }
 
     pub fn peer_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn recv_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
-        match self.0 {}
+        self.0
     }
 
     pub fn peek_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
-        match self.0 {}
+        self.0
     }
 
     pub fn send_to(&self, _: &[u8], _: &SocketAddr) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn duplicate(&self) -> io::Result<UdpSocket> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_read_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_write_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_broadcast(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn broadcast(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_multicast_loop_v4(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn multicast_loop_v4(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_multicast_ttl_v4(&self, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_multicast_loop_v6(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn multicast_loop_v6(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn join_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn join_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn leave_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn leave_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_ttl(&self, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn ttl(&self) -> io::Result<u32> {
-        match self.0 {}
+        self.0
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn recv(&self, _: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn peek(&self, _: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn send(&self, _: &[u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn connect(&self, _: io::Result<&SocketAddr>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for UdpSocket {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -470,14 +470,14 @@ impl LookupHost {
     }
 
     pub fn port(&self) -> u16 {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Iterator for LookupHost {
     type Item = SocketAddr;
     fn next(&mut self) -> Option<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/sgx/os.rs b/library/std/src/sys/sgx/os.rs
index ff1f9c368a3..144248d60c9 100644
--- a/library/std/src/sys/sgx/os.rs
+++ b/library/std/src/sys/sgx/os.rs
@@ -5,6 +5,7 @@ use crate::error::Error as StdError;
 use crate::ffi::{OsStr, OsString};
 use crate::fmt;
 use crate::io;
+use crate::marker::PhantomData;
 use crate::path::{self, PathBuf};
 use crate::str;
 use crate::sync::atomic::{AtomicUsize, Ordering};
@@ -35,7 +36,7 @@ pub fn chdir(_: &path::Path) -> io::Result<()> {
     sgx_ineffective(())
 }
 
-pub struct SplitPaths<'a>(&'a !);
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
 
 pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
     panic!("unsupported")
@@ -44,7 +45,7 @@ pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
 impl<'a> Iterator for SplitPaths<'a> {
     type Item = PathBuf;
     fn next(&mut self) -> Option<PathBuf> {
-        match *self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/unsupported/fs.rs b/library/std/src/sys/unsupported/fs.rs
index f5a0c89fe10..cd533761e37 100644
--- a/library/std/src/sys/unsupported/fs.rs
+++ b/library/std/src/sys/unsupported/fs.rs
@@ -26,55 +26,55 @@ pub struct DirBuilder {}
 
 impl FileAttr {
     pub fn size(&self) -> u64 {
-        match self.0 {}
+        self.0
     }
 
     pub fn perm(&self) -> FilePermissions {
-        match self.0 {}
+        self.0
     }
 
     pub fn file_type(&self) -> FileType {
-        match self.0 {}
+        self.0
     }
 
     pub fn modified(&self) -> io::Result<SystemTime> {
-        match self.0 {}
+        self.0
     }
 
     pub fn accessed(&self) -> io::Result<SystemTime> {
-        match self.0 {}
+        self.0
     }
 
     pub fn created(&self) -> io::Result<SystemTime> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for FileAttr {
     fn clone(&self) -> FileAttr {
-        match self.0 {}
+        self.0
     }
 }
 
 impl FilePermissions {
     pub fn readonly(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_readonly(&mut self, _readonly: bool) {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for FilePermissions {
     fn clone(&self) -> FilePermissions {
-        match self.0 {}
+        self.0
     }
 }
 
 impl PartialEq for FilePermissions {
     fn eq(&self, _other: &FilePermissions) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -82,27 +82,27 @@ impl Eq for FilePermissions {}
 
 impl fmt::Debug for FilePermissions {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
 impl FileType {
     pub fn is_dir(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_file(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_symlink(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for FileType {
     fn clone(&self) -> FileType {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -110,7 +110,7 @@ impl Copy for FileType {}
 
 impl PartialEq for FileType {
     fn eq(&self, _other: &FileType) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -118,19 +118,19 @@ impl Eq for FileType {}
 
 impl Hash for FileType {
     fn hash<H: Hasher>(&self, _h: &mut H) {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for FileType {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for ReadDir {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -138,25 +138,25 @@ impl Iterator for ReadDir {
     type Item = io::Result<DirEntry>;
 
     fn next(&mut self) -> Option<io::Result<DirEntry>> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl DirEntry {
     pub fn path(&self) -> PathBuf {
-        match self.0 {}
+        self.0
     }
 
     pub fn file_name(&self) -> OsString {
-        match self.0 {}
+        self.0
     }
 
     pub fn metadata(&self) -> io::Result<FileAttr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn file_type(&self) -> io::Result<FileType> {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -179,59 +179,59 @@ impl File {
     }
 
     pub fn file_attr(&self) -> io::Result<FileAttr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn fsync(&self) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn datasync(&self) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn truncate(&self, _size: u64) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read(&self, _buf: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read_vectored(&self, _bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_read_vectored(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn write(&self, _buf: &[u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn write_vectored(&self, _bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_write_vectored(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn flush(&self) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn seek(&self, _pos: SeekFrom) -> io::Result<u64> {
-        match self.0 {}
+        self.0
     }
 
     pub fn duplicate(&self) -> io::Result<File> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_permissions(&self, _perm: FilePermissions) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -247,7 +247,7 @@ impl DirBuilder {
 
 impl fmt::Debug for File {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/unsupported/net.rs b/library/std/src/sys/unsupported/net.rs
index 204a24cfc71..96203c74b57 100644
--- a/library/std/src/sys/unsupported/net.rs
+++ b/library/std/src/sys/unsupported/net.rs
@@ -17,93 +17,93 @@ impl TcpStream {
     }
 
     pub fn set_read_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_write_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn peek(&self, _: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read(&self, _: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read_vectored(&self, _: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_read_vectored(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn write(&self, _: &[u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn write_vectored(&self, _: &[IoSlice<'_>]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_write_vectored(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn peer_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn shutdown(&self, _: Shutdown) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn duplicate(&self) -> io::Result<TcpStream> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_nodelay(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn nodelay(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_ttl(&self, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn ttl(&self) -> io::Result<u32> {
-        match self.0 {}
+        self.0
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for TcpStream {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -115,45 +115,45 @@ impl TcpListener {
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
-        match self.0 {}
+        self.0
     }
 
     pub fn duplicate(&self) -> io::Result<TcpListener> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_ttl(&self, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn ttl(&self) -> io::Result<u32> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_only_v6(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn only_v6(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for TcpListener {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -165,129 +165,129 @@ impl UdpSocket {
     }
 
     pub fn peer_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn socket_addr(&self) -> io::Result<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 
     pub fn recv_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
-        match self.0 {}
+        self.0
     }
 
     pub fn peek_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
-        match self.0 {}
+        self.0
     }
 
     pub fn send_to(&self, _: &[u8], _: &SocketAddr) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn duplicate(&self) -> io::Result<UdpSocket> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_read_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_write_timeout(&self, _: Option<Duration>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_broadcast(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn broadcast(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_multicast_loop_v4(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn multicast_loop_v4(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_multicast_ttl_v4(&self, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_multicast_loop_v6(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn multicast_loop_v6(&self) -> io::Result<bool> {
-        match self.0 {}
+        self.0
     }
 
     pub fn join_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn join_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn leave_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn leave_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_ttl(&self, _: u32) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn ttl(&self) -> io::Result<u32> {
-        match self.0 {}
+        self.0
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
-        match self.0 {}
+        self.0
     }
 
     pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn recv(&self, _: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn peek(&self, _: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn send(&self, _: &[u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn connect(&self, _: io::Result<&SocketAddr>) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Debug for UdpSocket {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -295,14 +295,14 @@ pub struct LookupHost(!);
 
 impl LookupHost {
     pub fn port(&self) -> u16 {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Iterator for LookupHost {
     type Item = SocketAddr;
     fn next(&mut self) -> Option<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/unsupported/os.rs b/library/std/src/sys/unsupported/os.rs
index 11583ae99d6..e30395a0b1d 100644
--- a/library/std/src/sys/unsupported/os.rs
+++ b/library/std/src/sys/unsupported/os.rs
@@ -3,6 +3,7 @@ use crate::error::Error as StdError;
 use crate::ffi::{OsStr, OsString};
 use crate::fmt;
 use crate::io;
+use crate::marker::PhantomData;
 use crate::path::{self, PathBuf};
 
 pub fn errno() -> i32 {
@@ -21,7 +22,7 @@ pub fn chdir(_: &path::Path) -> io::Result<()> {
     unsupported()
 }
 
-pub struct SplitPaths<'a>(&'a !);
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
 
 pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
     panic!("unsupported")
@@ -30,7 +31,7 @@ pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
 impl<'a> Iterator for SplitPaths<'a> {
     type Item = PathBuf;
     fn next(&mut self) -> Option<PathBuf> {
-        match *self.0 {}
+        self.0
     }
 }
 
@@ -67,7 +68,7 @@ pub struct Env(!);
 impl Iterator for Env {
     type Item = (OsString, OsString);
     fn next(&mut self) -> Option<(OsString, OsString)> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/unsupported/pipe.rs b/library/std/src/sys/unsupported/pipe.rs
index 7ea46990d77..25514c2322f 100644
--- a/library/std/src/sys/unsupported/pipe.rs
+++ b/library/std/src/sys/unsupported/pipe.rs
@@ -4,31 +4,31 @@ pub struct AnonPipe(!);
 
 impl AnonPipe {
     pub fn read(&self, _buf: &mut [u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn read_vectored(&self, _bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_read_vectored(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn write(&self, _buf: &[u8]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn write_vectored(&self, _bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        match self.0 {}
+        self.0
     }
 
     pub fn is_write_vectored(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn diverge(&self) -> ! {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/unsupported/process.rs b/library/std/src/sys/unsupported/process.rs
index f777e40873f..38ac0a1ddd5 100644
--- a/library/std/src/sys/unsupported/process.rs
+++ b/library/std/src/sys/unsupported/process.rs
@@ -98,17 +98,17 @@ pub struct ExitStatus(!);
 
 impl ExitStatus {
     pub fn success(&self) -> bool {
-        match self.0 {}
+        self.0
     }
 
     pub fn code(&self) -> Option<i32> {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Clone for ExitStatus {
     fn clone(&self) -> ExitStatus {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -116,7 +116,7 @@ impl Copy for ExitStatus {}
 
 impl PartialEq for ExitStatus {
     fn eq(&self, _other: &ExitStatus) -> bool {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -124,13 +124,13 @@ impl Eq for ExitStatus {}
 
 impl fmt::Debug for ExitStatus {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
 impl fmt::Display for ExitStatus {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0 {}
+        self.0
     }
 }
 
@@ -150,19 +150,19 @@ pub struct Process(!);
 
 impl Process {
     pub fn id(&self) -> u32 {
-        match self.0 {}
+        self.0
     }
 
     pub fn kill(&mut self) -> io::Result<()> {
-        match self.0 {}
+        self.0
     }
 
     pub fn wait(&mut self) -> io::Result<ExitStatus> {
-        match self.0 {}
+        self.0
     }
 
     pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/unsupported/thread.rs b/library/std/src/sys/unsupported/thread.rs
index 7d5d2c61157..cda8510e1ba 100644
--- a/library/std/src/sys/unsupported/thread.rs
+++ b/library/std/src/sys/unsupported/thread.rs
@@ -26,7 +26,7 @@ impl Thread {
     }
 
     pub fn join(self) {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/wasi/net.rs b/library/std/src/sys/wasi/net.rs
index 30c21a05a32..06860673d90 100644
--- a/library/std/src/sys/wasi/net.rs
+++ b/library/std/src/sys/wasi/net.rs
@@ -347,14 +347,14 @@ pub struct LookupHost(!);
 
 impl LookupHost {
     pub fn port(&self) -> u16 {
-        match self.0 {}
+        self.0
     }
 }
 
 impl Iterator for LookupHost {
     type Item = SocketAddr;
     fn next(&mut self) -> Option<SocketAddr> {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/wasi/os.rs b/library/std/src/sys/wasi/os.rs
index a349c149249..cf17ac0ba5f 100644
--- a/library/std/src/sys/wasi/os.rs
+++ b/library/std/src/sys/wasi/os.rs
@@ -87,7 +87,7 @@ pub fn chdir(p: &path::Path) -> io::Result<()> {
     }
 }
 
-pub struct SplitPaths<'a>(&'a !);
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
 
 pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
     panic!("unsupported")
@@ -96,7 +96,7 @@ pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
 impl<'a> Iterator for SplitPaths<'a> {
     type Item = PathBuf;
     fn next(&mut self) -> Option<PathBuf> {
-        match *self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/wasi/thread.rs b/library/std/src/sys/wasi/thread.rs
index 2efa91f8b70..74515553a82 100644
--- a/library/std/src/sys/wasi/thread.rs
+++ b/library/std/src/sys/wasi/thread.rs
@@ -59,7 +59,7 @@ impl Thread {
     }
 
     pub fn join(self) {
-        match self.0 {}
+        self.0
     }
 }
 
diff --git a/library/std/src/sys/wasm/thread.rs b/library/std/src/sys/wasm/thread.rs
index 77f8c79ced9..b7bf95c89b4 100644
--- a/library/std/src/sys/wasm/thread.rs
+++ b/library/std/src/sys/wasm/thread.rs
@@ -47,7 +47,7 @@ impl Thread {
     }
 
     pub fn join(self) {
-        match self.0 {}
+        self.0
     }
 }