Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add #[must_use] to remaining std functions (A-N) #90430

Merged
merged 1 commit into from
Oct 31, 2021
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions library/std/src/backtrace.rs
Original file line number Diff line number Diff line change
Expand Up @@ -110,6 +110,7 @@ use crate::vec::Vec;
/// previous point in time. In some instances the `Backtrace` type may
/// internally be empty due to configuration. For more information see
/// `Backtrace::capture`.
#[must_use]
pub struct Backtrace {
inner: Inner,
}
Expand Down Expand Up @@ -355,6 +356,7 @@ impl Backtrace {
/// Returns the status of this backtrace, indicating whether this backtrace
/// request was unsupported, disabled, or a stack trace was actually
/// captured.
#[must_use]
pub fn status(&self) -> BacktraceStatus {
match self.inner {
Inner::Unsupported => BacktraceStatus::Unsupported,
Expand All @@ -366,6 +368,7 @@ impl Backtrace {

impl<'a> Backtrace {
/// Returns an iterator over the backtrace frames.
#[must_use]
#[unstable(feature = "backtrace_frames", issue = "79676")]
pub fn frames(&'a self) -> &'a [BacktraceFrame] {
if let Inner::Captured(c) = &self.inner { &c.force().frames } else { &[] }
Expand Down
5 changes: 5 additions & 0 deletions library/std/src/collections/hash/map.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1707,13 +1707,15 @@ impl<'a, K, V, S> RawEntryMut<'a, K, V, S> {
impl<'a, K, V, S> RawOccupiedEntryMut<'a, K, V, S> {
/// Gets a reference to the key in the entry.
#[inline]
#[must_use]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn key(&self) -> &K {
self.base.key()
}

/// Gets a mutable reference to the key in the entry.
#[inline]
#[must_use]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn key_mut(&mut self) -> &mut K {
self.base.key_mut()
Expand All @@ -1730,6 +1732,7 @@ impl<'a, K, V, S> RawOccupiedEntryMut<'a, K, V, S> {

/// Gets a reference to the value in the entry.
#[inline]
#[must_use]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get(&self) -> &V {
self.base.get()
Expand All @@ -1746,13 +1749,15 @@ impl<'a, K, V, S> RawOccupiedEntryMut<'a, K, V, S> {

/// Gets a mutable reference to the value in the entry.
#[inline]
#[must_use]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get_mut(&mut self) -> &mut V {
self.base.get_mut()
}

/// Gets a reference to the key and value in the entry.
#[inline]
#[must_use]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get_key_value(&mut self) -> (&K, &V) {
self.base.get_key_value()
Expand Down
8 changes: 8 additions & 0 deletions library/std/src/env.rs
Original file line number Diff line number Diff line change
Expand Up @@ -113,6 +113,7 @@ pub struct VarsOs {
/// ```
///
/// [`env::vars_os()`]: vars_os
#[must_use]
#[stable(feature = "env", since = "1.0.0")]
pub fn vars() -> Vars {
Vars { inner: vars_os() }
Expand Down Expand Up @@ -140,6 +141,7 @@ pub fn vars() -> Vars {
/// println!("{:?}: {:?}", key, value);
/// }
/// ```
#[must_use]
#[stable(feature = "env", since = "1.0.0")]
pub fn vars_os() -> VarsOs {
VarsOs { inner: os_imp::env() }
Expand Down Expand Up @@ -244,6 +246,7 @@ fn _var(key: &OsStr) -> Result<String, VarError> {
/// None => println!("{} is not defined in the environment.", key)
/// }
/// ```
#[must_use]
#[stable(feature = "env", since = "1.0.0")]
pub fn var_os<K: AsRef<OsStr>>(key: K) -> Option<OsString> {
_var_os(key.as_ref())
Expand Down Expand Up @@ -384,6 +387,7 @@ fn _remove_var(key: &OsStr) {
/// documentation for more.
///
/// [`env::split_paths()`]: split_paths
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "env", since = "1.0.0")]
pub struct SplitPaths<'a> {
inner: os_imp::SplitPaths<'a>,
Expand Down Expand Up @@ -564,6 +568,7 @@ impl Error for JoinPathsError {
reason = "This function's behavior is unexpected and probably not what you want. \
Consider using a crate from crates.io instead."
)]
#[must_use]
#[stable(feature = "env", since = "1.0.0")]
pub fn home_dir() -> Option<PathBuf> {
os_imp::home_dir()
Expand Down Expand Up @@ -603,6 +608,7 @@ pub fn home_dir() -> Option<PathBuf> {
/// println!("Temporary directory: {}", dir.display());
/// }
/// ```
#[must_use]
#[stable(feature = "env", since = "1.0.0")]
pub fn temp_dir() -> PathBuf {
os_imp::temp_dir()
Expand Down Expand Up @@ -690,6 +696,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
/// should not be relied upon for security purposes.
///
/// [`env::args()`]: args
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "env", since = "1.0.0")]
pub struct Args {
inner: ArgsOs,
Expand All @@ -706,6 +713,7 @@ pub struct Args {
/// should not be relied upon for security purposes.
///
/// [`env::args_os()`]: args_os
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "env", since = "1.0.0")]
pub struct ArgsOs {
inner: sys::args::Args,
Expand Down
3 changes: 3 additions & 0 deletions library/std/src/ffi/c_str.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1009,6 +1009,7 @@ impl NulError {
/// let nul_error = CString::new("foo bar\0").unwrap_err();
/// assert_eq!(nul_error.nul_position(), 7);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn nul_position(&self) -> usize {
self.0
Expand Down Expand Up @@ -1107,6 +1108,7 @@ impl IntoStringError {
}

/// Access the underlying UTF-8 error that was the cause of this error.
#[must_use]
#[stable(feature = "cstring_into", since = "1.7.0")]
pub fn utf8_error(&self) -> Utf8Error {
self.error
Expand Down Expand Up @@ -1456,6 +1458,7 @@ impl CStr {
/// let boxed = c_string.into_boxed_c_str();
/// assert_eq!(boxed.into_c_string(), CString::new("foo").expect("CString::new failed"));
/// ```
#[must_use = "`self` will be dropped if the result is not used"]
#[stable(feature = "into_boxed_c_str", since = "1.20.0")]
pub fn into_c_string(self: Box<CStr>) -> CString {
let raw = Box::into_raw(self) as *mut [u8];
Expand Down
2 changes: 2 additions & 0 deletions library/std/src/ffi/os_str.rs
Original file line number Diff line number Diff line change
Expand Up @@ -239,6 +239,7 @@ impl OsString {
/// assert!(os_string.capacity() >= 10);
/// ```
#[stable(feature = "osstring_simple_functions", since = "1.9.0")]
#[must_use]
#[inline]
pub fn capacity(&self) -> usize {
self.inner.capacity()
Expand Down Expand Up @@ -707,6 +708,7 @@ impl OsStr {

/// Converts a <code>[Box]<[OsStr]></code> into an [`OsString`] without copying or allocating.
#[stable(feature = "into_boxed_os_str", since = "1.20.0")]
#[must_use = "`self` will be dropped if the result is not used"]
pub fn into_os_string(self: Box<OsStr>) -> OsString {
let boxed = unsafe { Box::from_raw(Box::into_raw(self) as *mut Slice) };
OsString { inner: Buf::from_box(boxed) }
Expand Down
6 changes: 6 additions & 0 deletions library/std/src/fs.rs
Original file line number Diff line number Diff line change
Expand Up @@ -374,6 +374,7 @@ impl File {
/// Ok(())
/// }
/// ```
#[must_use]
#[unstable(feature = "with_options", issue = "65439")]
pub fn with_options() -> OpenOptions {
OpenOptions::new()
Expand Down Expand Up @@ -983,6 +984,7 @@ impl Metadata {
/// Ok(())
/// }
/// ```
#[must_use]
#[stable(feature = "file_type", since = "1.1.0")]
pub fn file_type(&self) -> FileType {
FileType(self.0.file_type())
Expand Down Expand Up @@ -1100,6 +1102,7 @@ impl Metadata {
/// Ok(())
/// }
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn permissions(&self) -> Permissions {
Permissions(self.0.perm())
Expand Down Expand Up @@ -1247,6 +1250,7 @@ impl Permissions {
/// Ok(())
/// }
/// ```
#[must_use = "call `set_readonly` to modify the readonly flag"]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn readonly(&self) -> bool {
self.0.readonly()
Expand Down Expand Up @@ -1441,6 +1445,7 @@ impl DirEntry {
/// ```
///
/// The exact text, of course, depends on what files you have in `.`.
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn path(&self) -> PathBuf {
self.0.path()
Expand Down Expand Up @@ -1536,6 +1541,7 @@ impl DirEntry {
/// }
/// }
/// ```
#[must_use]
#[stable(feature = "dir_entry_ext", since = "1.1.0")]
pub fn file_name(&self) -> OsString {
self.0.file_name()
Expand Down
5 changes: 5 additions & 0 deletions library/std/src/io/error.rs
Original file line number Diff line number Diff line change
Expand Up @@ -442,6 +442,7 @@ impl Error {
/// println!("last OS error: {:?}", Error::last_os_error());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn last_os_error() -> Error {
Error::from_raw_os_error(sys::os::errno() as i32)
Expand Down Expand Up @@ -509,6 +510,7 @@ impl Error {
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn raw_os_error(&self) -> Option<i32> {
match self.repr {
Expand Down Expand Up @@ -547,6 +549,7 @@ impl Error {
/// }
/// ```
#[stable(feature = "io_error_inner", since = "1.3.0")]
#[must_use]
#[inline]
pub fn get_ref(&self) -> Option<&(dyn error::Error + Send + Sync + 'static)> {
match self.repr {
Expand Down Expand Up @@ -620,6 +623,7 @@ impl Error {
/// }
/// ```
#[stable(feature = "io_error_inner", since = "1.3.0")]
#[must_use]
#[inline]
pub fn get_mut(&mut self) -> Option<&mut (dyn error::Error + Send + Sync + 'static)> {
match self.repr {
Expand Down Expand Up @@ -688,6 +692,7 @@ impl Error {
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
pub fn kind(&self) -> ErrorKind {
match self.repr {
Expand Down
3 changes: 3 additions & 0 deletions library/std/src/io/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1310,6 +1310,7 @@ pub struct Initializer(bool);
impl Initializer {
/// Returns a new `Initializer` which will zero out buffers.
#[unstable(feature = "read_initializer", issue = "42788")]
#[must_use]
#[inline]
pub fn zeroing() -> Initializer {
Initializer(true)
Expand All @@ -1324,13 +1325,15 @@ impl Initializer {
/// the method accurately reflects the number of bytes that have been
/// written to the head of the buffer.
#[unstable(feature = "read_initializer", issue = "42788")]
#[must_use]
#[inline]
pub unsafe fn nop() -> Initializer {
Initializer(false)
}

/// Indicates if a buffer should be initialized.
#[unstable(feature = "read_initializer", issue = "42788")]
#[must_use]
#[inline]
pub fn should_initialize(&self) -> bool {
self.0
Expand Down
3 changes: 3 additions & 0 deletions library/std/src/io/stdio.rs
Original file line number Diff line number Diff line change
Expand Up @@ -301,6 +301,7 @@ pub struct StdinLock<'a> {
/// Ok(())
/// }
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn stdin() -> Stdin {
static INSTANCE: SyncOnceCell<Mutex<BufReader<StdinRaw>>> = SyncOnceCell::new();
Expand Down Expand Up @@ -673,6 +674,7 @@ static STDOUT: SyncOnceCell<ReentrantMutex<RefCell<LineWriter<StdoutRaw>>>> = Sy
/// Ok(())
/// }
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn stdout() -> Stdout {
Stdout {
Expand Down Expand Up @@ -953,6 +955,7 @@ pub struct StderrLock<'a> {
/// Ok(())
/// }
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn stderr() -> Stderr {
// Note that unlike `stdout()` we don't use `at_exit` here to register a
Expand Down
3 changes: 3 additions & 0 deletions library/std/src/io/util.rs
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@ pub struct Empty;
/// io::empty().read_to_string(&mut buffer).unwrap();
/// assert!(buffer.is_empty());
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_io_structs", issue = "78812")]
pub const fn empty() -> Empty {
Expand Down Expand Up @@ -112,6 +113,7 @@ pub struct Repeat {
/// io::repeat(0b101).read_exact(&mut buffer).unwrap();
/// assert_eq!(buffer, [0b101, 0b101, 0b101]);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_io_structs", issue = "78812")]
pub const fn repeat(byte: u8) -> Repeat {
Expand Down Expand Up @@ -192,6 +194,7 @@ pub struct Sink;
/// let num_bytes = io::sink().write(&buffer).unwrap();
/// assert_eq!(num_bytes, 5);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_io_structs", issue = "78812")]
pub const fn sink() -> Sink {
Expand Down
8 changes: 8 additions & 0 deletions library/std/src/net/addr.rs
Original file line number Diff line number Diff line change
Expand Up @@ -149,6 +149,7 @@ impl SocketAddr {
/// let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
/// assert_eq!(socket.ip(), IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
/// ```
#[must_use]
#[stable(feature = "ip_addr", since = "1.7.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn ip(&self) -> IpAddr {
Expand Down Expand Up @@ -189,6 +190,7 @@ impl SocketAddr {
/// let socket = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
/// assert_eq!(socket.port(), 8080);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn port(&self) -> u16 {
Expand Down Expand Up @@ -297,6 +299,7 @@ impl SocketAddrV4 {
/// let socket = SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080);
/// assert_eq!(socket.ip(), &Ipv4Addr::new(127, 0, 0, 1));
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn ip(&self) -> &Ipv4Addr {
Expand Down Expand Up @@ -331,6 +334,7 @@ impl SocketAddrV4 {
/// let socket = SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080);
/// assert_eq!(socket.port(), 8080);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn port(&self) -> u16 {
Expand Down Expand Up @@ -396,6 +400,7 @@ impl SocketAddrV6 {
/// let socket = SocketAddrV6::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 8080, 0, 0);
/// assert_eq!(socket.ip(), &Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1));
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn ip(&self) -> &Ipv6Addr {
Expand Down Expand Up @@ -428,6 +433,7 @@ impl SocketAddrV6 {
/// let socket = SocketAddrV6::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 8080, 0, 0);
/// assert_eq!(socket.port(), 8080);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn port(&self) -> u16 {
Expand Down Expand Up @@ -470,6 +476,7 @@ impl SocketAddrV6 {
/// let socket = SocketAddrV6::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 8080, 10, 0);
/// assert_eq!(socket.flowinfo(), 10);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn flowinfo(&self) -> u32 {
Expand Down Expand Up @@ -509,6 +516,7 @@ impl SocketAddrV6 {
/// let socket = SocketAddrV6::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 8080, 0, 78);
/// assert_eq!(socket.scope_id(), 78);
/// ```
#[must_use]
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_socketaddr", issue = "82485")]
pub const fn scope_id(&self) -> u32 {
Expand Down
Loading