From 06e625f7d582601f5e2ff69ba80f6d3a11632b24 Mon Sep 17 00:00:00 2001 From: John Kugelman Date: Mon, 11 Oct 2021 13:57:38 -0400 Subject: [PATCH] Add #[must_use] to as_type conversions --- library/alloc/src/collections/binary_heap.rs | 1 + library/alloc/src/collections/linked_list.rs | 1 + library/alloc/src/rc.rs | 1 + library/alloc/src/string.rs | 5 +++++ library/alloc/src/sync.rs | 2 ++ library/alloc/src/vec/drain.rs | 1 + library/core/src/fmt/mod.rs | 1 + library/core/src/option.rs | 2 ++ library/core/src/ptr/non_null.rs | 9 +++++++++ library/core/src/ptr/unique.rs | 2 ++ library/core/src/slice/iter.rs | 2 ++ library/core/src/str/iter.rs | 4 ++++ library/core/src/str/mod.rs | 4 ++++ library/core/src/time.rs | 6 ++++++ library/std/src/ffi/c_str.rs | 5 +++++ library/std/src/ffi/os_str.rs | 1 + library/std/src/os/unix/net/addr.rs | 1 + library/std/src/path.rs | 5 +++++ library/std/src/thread/mod.rs | 1 + 19 files changed, 54 insertions(+) diff --git a/library/alloc/src/collections/binary_heap.rs b/library/alloc/src/collections/binary_heap.rs index 75720a970a31f..9bc9c6ef1629f 100644 --- a/library/alloc/src/collections/binary_heap.rs +++ b/library/alloc/src/collections/binary_heap.rs @@ -1007,6 +1007,7 @@ impl BinaryHeap { /// /// io::sink().write(heap.as_slice()).unwrap(); /// ``` + #[must_use] #[unstable(feature = "binary_heap_as_slice", issue = "83659")] pub fn as_slice(&self) -> &[T] { self.data.as_slice() diff --git a/library/alloc/src/collections/linked_list.rs b/library/alloc/src/collections/linked_list.rs index a769c558b4fa9..82e866c950457 100644 --- a/library/alloc/src/collections/linked_list.rs +++ b/library/alloc/src/collections/linked_list.rs @@ -1384,6 +1384,7 @@ impl<'a, T> CursorMut<'a, T> { /// The lifetime of the returned `Cursor` is bound to that of the /// `CursorMut`, which means it cannot outlive the `CursorMut` and that the /// `CursorMut` is frozen for the lifetime of the `Cursor`. + #[must_use] #[unstable(feature = "linked_list_cursors", issue = "58533")] pub fn as_cursor(&self) -> Cursor<'_, T> { Cursor { list: self.list, current: self.current, index: self.index } diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs index c6573597b1e8c..c337b7c5a5901 100644 --- a/library/alloc/src/rc.rs +++ b/library/alloc/src/rc.rs @@ -2087,6 +2087,7 @@ impl Weak { /// ``` /// /// [`null`]: ptr::null + #[must_use] #[stable(feature = "rc_as_ptr", since = "1.45.0")] pub fn as_ptr(&self) -> *const T { let ptr: *mut RcBox = NonNull::as_ptr(self.ptr); diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs index d00792b9c3e71..4be8dddeda83d 100644 --- a/library/alloc/src/string.rs +++ b/library/alloc/src/string.rs @@ -800,6 +800,7 @@ impl String { /// assert_eq!("foo", s.as_str()); /// ``` #[inline] + #[must_use] #[stable(feature = "string_as_str", since = "1.7.0")] pub fn as_str(&self) -> &str { self @@ -820,6 +821,7 @@ impl String { /// assert_eq!("FOOBAR", s_mut_str); /// ``` #[inline] + #[must_use] #[stable(feature = "string_as_str", since = "1.7.0")] pub fn as_mut_str(&mut self) -> &mut str { self @@ -1160,6 +1162,7 @@ impl String { /// assert_eq!(&[104, 101, 108, 108, 111], s.as_bytes()); /// ``` #[inline] + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub fn as_bytes(&self) -> &[u8] { &self.vec @@ -1763,6 +1766,7 @@ impl FromUtf8Error { /// /// assert_eq!(&[0, 159], value.unwrap_err().as_bytes()); /// ``` + #[must_use] #[stable(feature = "from_utf8_error_as_bytes", since = "1.26.0")] pub fn as_bytes(&self) -> &[u8] { &self.bytes[..] @@ -2779,6 +2783,7 @@ impl<'a> Drain<'a> { /// let _ = drain.next().unwrap(); /// assert_eq!(drain.as_str(), "bc"); /// ``` + #[must_use] #[stable(feature = "string_drain_as_str", since = "1.55.0")] pub fn as_str(&self) -> &str { self.iter.as_str() diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs index 7dd1bc5156039..d0bbab514665f 100644 --- a/library/alloc/src/sync.rs +++ b/library/alloc/src/sync.rs @@ -822,6 +822,7 @@ impl Arc { /// assert_eq!(x_ptr, Arc::as_ptr(&y)); /// assert_eq!(unsafe { &*x_ptr }, "hello"); /// ``` + #[must_use] #[stable(feature = "rc_as_ptr", since = "1.45.0")] pub fn as_ptr(this: &Self) -> *const T { let ptr: *mut ArcInner = NonNull::as_ptr(this.ptr); @@ -1718,6 +1719,7 @@ impl Weak { /// ``` /// /// [`null`]: core::ptr::null "ptr::null" + #[must_use] #[stable(feature = "weak_into_raw", since = "1.45.0")] pub fn as_ptr(&self) -> *const T { let ptr: *mut ArcInner = NonNull::as_ptr(self.ptr); diff --git a/library/alloc/src/vec/drain.rs b/library/alloc/src/vec/drain.rs index fb32d144f872c..e643940d017ba 100644 --- a/library/alloc/src/vec/drain.rs +++ b/library/alloc/src/vec/drain.rs @@ -52,6 +52,7 @@ impl<'a, T, A: Allocator> Drain<'a, T, A> { /// let _ = drain.next().unwrap(); /// assert_eq!(drain.as_slice(), &['b', 'c']); /// ``` + #[must_use] #[stable(feature = "vec_drain_as_slice", since = "1.46.0")] pub fn as_slice(&self) -> &[T] { self.iter.as_slice() diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs index d10563a40976d..b8ad7720e0c55 100644 --- a/library/core/src/fmt/mod.rs +++ b/library/core/src/fmt/mod.rs @@ -491,6 +491,7 @@ impl<'a> Arguments<'a> { /// ``` #[stable(feature = "fmt_as_str", since = "1.52.0")] #[rustc_const_unstable(feature = "const_arguments_as_str", issue = "none")] + #[must_use] #[inline] pub const fn as_str(&self) -> Option<&'static str> { match (self.pieces, self.args) { diff --git a/library/core/src/option.rs b/library/core/src/option.rs index df8af22a317bc..401267f5613ee 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -657,6 +657,7 @@ impl Option { /// /// [&]: reference "shared reference" #[inline] + #[must_use] #[stable(feature = "pin", since = "1.33.0")] pub fn as_pin_ref(self: Pin<&Self>) -> Option> { // SAFETY: `x` is guaranteed to be pinned because it comes from `self` @@ -668,6 +669,7 @@ impl Option { /// /// [&mut]: reference "mutable reference" #[inline] + #[must_use] #[stable(feature = "pin", since = "1.33.0")] pub fn as_pin_mut(self: Pin<&mut Self>) -> Option> { // SAFETY: `get_unchecked_mut` is never used to move the `Option` inside `self`. diff --git a/library/core/src/ptr/non_null.rs b/library/core/src/ptr/non_null.rs index 87c8674af0dc5..af9daf8297401 100644 --- a/library/core/src/ptr/non_null.rs +++ b/library/core/src/ptr/non_null.rs @@ -119,6 +119,7 @@ impl NonNull { /// /// [the module documentation]: crate::ptr#safety #[inline] + #[must_use] #[unstable(feature = "ptr_as_uninit", issue = "75402")] pub unsafe fn as_uninit_ref<'a>(&self) -> &'a MaybeUninit { // SAFETY: the caller must guarantee that `self` meets all the @@ -151,6 +152,7 @@ impl NonNull { /// /// [the module documentation]: crate::ptr#safety #[inline] + #[must_use] #[unstable(feature = "ptr_as_uninit", issue = "75402")] pub unsafe fn as_uninit_mut<'a>(&mut self) -> &'a mut MaybeUninit { // SAFETY: the caller must guarantee that `self` meets all the @@ -264,6 +266,7 @@ impl NonNull { /// ``` #[stable(feature = "nonnull", since = "1.25.0")] #[rustc_const_stable(feature = "const_nonnull_as_ptr", since = "1.32.0")] + #[must_use] #[inline] pub const fn as_ptr(self) -> *mut T { self.pointer as *mut T @@ -310,6 +313,7 @@ impl NonNull { /// /// [the module documentation]: crate::ptr#safety #[stable(feature = "nonnull", since = "1.25.0")] + #[must_use] #[inline] pub unsafe fn as_ref<'a>(&self) -> &'a T { // SAFETY: the caller must guarantee that `self` meets all the @@ -359,6 +363,7 @@ impl NonNull { /// /// [the module documentation]: crate::ptr#safety #[stable(feature = "nonnull", since = "1.25.0")] + #[must_use] #[inline] pub unsafe fn as_mut<'a>(&mut self) -> &'a mut T { // SAFETY: the caller must guarantee that `self` meets all the @@ -455,6 +460,7 @@ impl NonNull<[T]> { /// assert_eq!(slice.as_non_null_ptr(), NonNull::new(1 as *mut i8).unwrap()); /// ``` #[inline] + #[must_use] #[unstable(feature = "slice_ptr_get", issue = "74265")] #[rustc_const_unstable(feature = "slice_ptr_get", issue = "74265")] pub const fn as_non_null_ptr(self) -> NonNull { @@ -474,6 +480,7 @@ impl NonNull<[T]> { /// assert_eq!(slice.as_mut_ptr(), 1 as *mut i8); /// ``` #[inline] + #[must_use] #[unstable(feature = "slice_ptr_get", issue = "74265")] #[rustc_const_unstable(feature = "slice_ptr_get", issue = "74265")] pub const fn as_mut_ptr(self) -> *mut T { @@ -518,6 +525,7 @@ impl NonNull<[T]> { /// /// [valid]: crate::ptr#safety #[inline] + #[must_use] #[unstable(feature = "ptr_as_uninit", issue = "75402")] pub unsafe fn as_uninit_slice<'a>(&self) -> &'a [MaybeUninit] { // SAFETY: the caller must uphold the safety contract for `as_uninit_slice`. @@ -579,6 +587,7 @@ impl NonNull<[T]> { /// # Ok::<_, std::alloc::AllocError>(()) /// ``` #[inline] + #[must_use] #[unstable(feature = "ptr_as_uninit", issue = "75402")] pub unsafe fn as_uninit_slice_mut<'a>(&self) -> &'a mut [MaybeUninit] { // SAFETY: the caller must uphold the safety contract for `as_uninit_slice_mut`. diff --git a/library/core/src/ptr/unique.rs b/library/core/src/ptr/unique.rs index b3deddca18efe..5baceefb504a5 100644 --- a/library/core/src/ptr/unique.rs +++ b/library/core/src/ptr/unique.rs @@ -112,6 +112,7 @@ impl Unique { /// The resulting lifetime is bound to self so this behaves "as if" /// it were actually an instance of T that is getting borrowed. If a longer /// (unbound) lifetime is needed, use `&*my_ptr.as_ptr()`. + #[must_use] #[inline] pub unsafe fn as_ref(&self) -> &T { // SAFETY: the caller must guarantee that `self` meets all the @@ -124,6 +125,7 @@ impl Unique { /// The resulting lifetime is bound to self so this behaves "as if" /// it were actually an instance of T that is getting borrowed. If a longer /// (unbound) lifetime is needed, use `&mut *my_ptr.as_ptr()`. + #[must_use] #[inline] pub unsafe fn as_mut(&mut self) -> &mut T { // SAFETY: the caller must guarantee that `self` meets all the diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs index 70e59cda63f26..dbf97851b03e4 100644 --- a/library/core/src/slice/iter.rs +++ b/library/core/src/slice/iter.rs @@ -124,6 +124,7 @@ impl<'a, T> Iter<'a, T> { /// // Now `as_slice` returns "[2, 3]": /// println!("{:?}", iter.as_slice()); /// ``` + #[must_use] #[stable(feature = "iter_to_slice", since = "1.4.0")] pub fn as_slice(&self) -> &'a [T] { self.make_slice() @@ -298,6 +299,7 @@ impl<'a, T> IterMut<'a, T> { /// // Now `as_slice` returns "[2, 3]": /// assert_eq!(iter.as_slice(), &[2, 3]); /// ``` + #[must_use] #[stable(feature = "slice_iter_mut_as_slice", since = "1.53.0")] pub fn as_slice(&self) -> &[T] { self.make_slice() diff --git a/library/core/src/str/iter.rs b/library/core/src/str/iter.rs index 8db9edc61472f..94cb81e9d41a1 100644 --- a/library/core/src/str/iter.rs +++ b/library/core/src/str/iter.rs @@ -109,6 +109,7 @@ impl<'a> Chars<'a> { /// assert_eq!(chars.as_str(), ""); /// ``` #[stable(feature = "iter_to_slice", since = "1.4.0")] + #[must_use] #[inline] pub fn as_str(&self) -> &'a str { // SAFETY: `Chars` is only made from a str, which guarantees the iter is valid UTF-8. @@ -185,6 +186,7 @@ impl<'a> CharIndices<'a> { /// This has the same lifetime as the original slice, and so the /// iterator can continue to be used while this exists. #[stable(feature = "iter_to_slice", since = "1.4.0")] + #[must_use] #[inline] pub fn as_str(&self) -> &'a str { self.iter.as_str() @@ -1247,6 +1249,7 @@ impl<'a> SplitWhitespace<'a> { /// assert_eq!(split.as_str(), ""); /// ``` #[inline] + #[must_use] #[unstable(feature = "str_split_whitespace_as_str", issue = "77998")] pub fn as_str(&self) -> &'a str { self.inner.iter.as_str() @@ -1302,6 +1305,7 @@ impl<'a> SplitAsciiWhitespace<'a> { /// assert_eq!(split.as_str(), ""); /// ``` #[inline] + #[must_use] #[unstable(feature = "str_split_whitespace_as_str", issue = "77998")] pub fn as_str(&self) -> &'a str { if self.inner.iter.iter.finished { diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs index 14ce94c178c5b..607a0179ff4b9 100644 --- a/library/core/src/str/mod.rs +++ b/library/core/src/str/mod.rs @@ -230,6 +230,7 @@ impl str { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "str_as_bytes", since = "1.39.0")] + #[must_use] #[inline(always)] #[allow(unused_attributes)] pub const fn as_bytes(&self) -> &[u8] { @@ -274,6 +275,7 @@ impl str { /// assert_eq!("🍔∈🌏", s); /// ``` #[stable(feature = "str_mut_extras", since = "1.20.0")] + #[must_use] #[inline(always)] pub unsafe fn as_bytes_mut(&mut self) -> &mut [u8] { // SAFETY: the cast from `&str` to `&[u8]` is safe since `str` @@ -304,6 +306,7 @@ impl str { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "rustc_str_as_ptr", since = "1.32.0")] + #[must_use] #[inline] pub const fn as_ptr(&self) -> *const u8 { self as *const str as *const u8 @@ -318,6 +321,7 @@ impl str { /// It is your responsibility to make sure that the string slice only gets /// modified in a way that it remains valid UTF-8. #[stable(feature = "str_as_mut_ptr", since = "1.36.0")] + #[must_use] #[inline] pub fn as_mut_ptr(&mut self) -> *mut u8 { self as *mut str as *mut u8 diff --git a/library/core/src/time.rs b/library/core/src/time.rs index e1408c7cc2ecc..3e853e28f14e9 100644 --- a/library/core/src/time.rs +++ b/library/core/src/time.rs @@ -329,6 +329,7 @@ impl Duration { /// [`subsec_nanos`]: Duration::subsec_nanos #[stable(feature = "duration", since = "1.3.0")] #[rustc_const_stable(feature = "duration", since = "1.32.0")] + #[must_use] #[inline] pub const fn as_secs(&self) -> u64 { self.secs @@ -412,6 +413,7 @@ impl Duration { /// ``` #[stable(feature = "duration_as_u128", since = "1.33.0")] #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")] + #[must_use] #[inline] pub const fn as_millis(&self) -> u128 { self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128 @@ -429,6 +431,7 @@ impl Duration { /// ``` #[stable(feature = "duration_as_u128", since = "1.33.0")] #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")] + #[must_use] #[inline] pub const fn as_micros(&self) -> u128 { self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128 @@ -446,6 +449,7 @@ impl Duration { /// ``` #[stable(feature = "duration_as_u128", since = "1.33.0")] #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")] + #[must_use] #[inline] pub const fn as_nanos(&self) -> u128 { self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128 @@ -669,6 +673,7 @@ impl Duration { /// assert_eq!(dur.as_secs_f64(), 2.7); /// ``` #[stable(feature = "duration_float", since = "1.38.0")] + #[must_use] #[inline] #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")] pub const fn as_secs_f64(&self) -> f64 { @@ -687,6 +692,7 @@ impl Duration { /// assert_eq!(dur.as_secs_f32(), 2.7); /// ``` #[stable(feature = "duration_float", since = "1.38.0")] + #[must_use] #[inline] #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")] pub const fn as_secs_f32(&self) -> f32 { diff --git a/library/std/src/ffi/c_str.rs b/library/std/src/ffi/c_str.rs index 6b488e49ed74b..8bf9f5dae6ea4 100644 --- a/library/std/src/ffi/c_str.rs +++ b/library/std/src/ffi/c_str.rs @@ -297,6 +297,7 @@ impl FromVecWithNulError { /// /// assert_eq!(&bytes[..], value.unwrap_err().as_bytes()); /// ``` + #[must_use] pub fn as_bytes(&self) -> &[u8] { &self.bytes[..] } @@ -616,6 +617,7 @@ impl CString { /// assert_eq!(bytes, &[b'f', b'o', b'o']); /// ``` #[inline] + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub fn as_bytes(&self) -> &[u8] { // SAFETY: CString has a length at least 1 @@ -635,6 +637,7 @@ impl CString { /// assert_eq!(bytes, &[b'f', b'o', b'o', b'\0']); /// ``` #[inline] + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub fn as_bytes_with_nul(&self) -> &[u8] { &self.inner @@ -653,6 +656,7 @@ impl CString { /// CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed")); /// ``` #[inline] + #[must_use] #[stable(feature = "as_c_str", since = "1.20.0")] pub fn as_c_str(&self) -> &CStr { &*self @@ -1308,6 +1312,7 @@ impl CStr { /// This way, the lifetime of the [`CString`] in `hello` encompasses /// the lifetime of `ptr` and the `unsafe` block. #[inline] + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_str_as_ptr", since = "1.32.0")] pub const fn as_ptr(&self) -> *const c_char { diff --git a/library/std/src/ffi/os_str.rs b/library/std/src/ffi/os_str.rs index f5cef60e1267a..844d866b3dd35 100644 --- a/library/std/src/ffi/os_str.rs +++ b/library/std/src/ffi/os_str.rs @@ -136,6 +136,7 @@ impl OsString { /// assert_eq!(os_string.as_os_str(), os_str); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] #[inline] pub fn as_os_str(&self) -> &OsStr { self diff --git a/library/std/src/os/unix/net/addr.rs b/library/std/src/os/unix/net/addr.rs index 62bfde8bfd436..d741096893a69 100644 --- a/library/std/src/os/unix/net/addr.rs +++ b/library/std/src/os/unix/net/addr.rs @@ -192,6 +192,7 @@ impl SocketAddr { /// } /// ``` #[stable(feature = "unix_socket", since = "1.10.0")] + #[must_use] pub fn as_pathname(&self) -> Option<&Path> { if let AddressKind::Pathname(path) = self.address() { Some(path) } else { None } } diff --git a/library/std/src/path.rs b/library/std/src/path.rs index 6bfc7b0a5c1df..6ad7e1dfdfded 100644 --- a/library/std/src/path.rs +++ b/library/std/src/path.rs @@ -427,6 +427,7 @@ impl<'a> PrefixComponent<'a> { /// Returns the raw [`OsStr`] slice for this prefix. #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] #[inline] pub fn as_os_str(&self) -> &'a OsStr { self.raw @@ -676,6 +677,7 @@ impl<'a> Components<'a> { /// /// assert_eq!(Path::new("foo/bar.txt"), components.as_path()); /// ``` + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub fn as_path(&self) -> &'a Path { let mut comps = self.clone(); @@ -821,6 +823,7 @@ impl<'a> Iter<'a> { /// assert_eq!(Path::new("foo/bar.txt"), iter.as_path()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] #[inline] pub fn as_path(&self) -> &'a Path { self.inner.as_path() @@ -1186,6 +1189,7 @@ impl PathBuf { /// assert_eq!(Path::new("/test"), p.as_path()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] #[inline] pub fn as_path(&self) -> &Path { self @@ -1921,6 +1925,7 @@ impl Path { /// assert_eq!(os_str, std::ffi::OsStr::new("foo.txt")); /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] #[inline] pub fn as_os_str(&self) -> &OsStr { &self.inner diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs index 7d404aff30e07..82847d83ad225 100644 --- a/library/std/src/thread/mod.rs +++ b/library/std/src/thread/mod.rs @@ -1031,6 +1031,7 @@ impl ThreadId { /// value is entirely opaque -- only equality testing is stable. Note that /// it is not guaranteed which values new threads will return, and this may /// change across Rust versions. + #[must_use] #[unstable(feature = "thread_id_value", issue = "67939")] pub fn as_u64(&self) -> NonZeroU64 { self.0