diff --git a/library/alloc/src/str.rs b/library/alloc/src/str.rs index 2900d01d9bdae..ac7f230445656 100644 --- a/library/alloc/src/str.rs +++ b/library/alloc/src/str.rs @@ -595,6 +595,7 @@ impl str { /// assert_eq!("☺", &*smile); /// ``` #[stable(feature = "str_box_extras", since = "1.20.0")] +#[must_use] #[inline] pub unsafe fn from_boxed_utf8_unchecked(v: Box<[u8]>) -> Box { unsafe { Box::from_raw(Box::into_raw(v) as *mut str) } diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs index d88b8e398985a..0c383b8bdb6c6 100644 --- a/library/alloc/src/string.rs +++ b/library/alloc/src/string.rs @@ -761,6 +761,7 @@ impl String { /// assert_eq!("💖", sparkle_heart); /// ``` #[inline] + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub unsafe fn from_utf8_unchecked(bytes: Vec) -> String { String { vec: bytes } diff --git a/library/core/src/alloc/layout.rs b/library/core/src/alloc/layout.rs index ccf6e420de7a9..8086dd357306e 100644 --- a/library/core/src/alloc/layout.rs +++ b/library/core/src/alloc/layout.rs @@ -94,6 +94,7 @@ impl Layout { /// [`Layout::from_size_align`]. #[stable(feature = "alloc_layout", since = "1.28.0")] #[rustc_const_stable(feature = "alloc_layout", since = "1.36.0")] + #[must_use] #[inline] pub const unsafe fn from_size_align_unchecked(size: usize, align: usize) -> Self { // SAFETY: the caller must ensure that `align` is greater than zero. diff --git a/library/core/src/char/convert.rs b/library/core/src/char/convert.rs index 7a0ec32cc61a9..72921414fb3f2 100644 --- a/library/core/src/char/convert.rs +++ b/library/core/src/char/convert.rs @@ -48,6 +48,7 @@ use super::MAX; /// assert_eq!(None, c); /// ``` #[doc(alias = "chr")] +#[must_use] #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn from_u32(i: u32) -> Option { @@ -88,6 +89,7 @@ pub fn from_u32(i: u32) -> Option { /// assert_eq!('❤', c); /// ``` #[inline] +#[must_use] #[stable(feature = "char_from_unchecked", since = "1.5.0")] pub unsafe fn from_u32_unchecked(i: u32) -> char { // SAFETY: the caller must guarantee that `i` is a valid char value. @@ -319,6 +321,7 @@ impl fmt::Display for CharTryFromError { /// let c = char::from_digit(1, 37); /// ``` #[inline] +#[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub fn from_digit(num: u32, radix: u32) -> Option { if radix > 36 { diff --git a/library/core/src/char/methods.rs b/library/core/src/char/methods.rs index b3af1f1ffb592..07ac08f45c79f 100644 --- a/library/core/src/char/methods.rs +++ b/library/core/src/char/methods.rs @@ -136,6 +136,7 @@ impl char { /// assert_eq!(None, c); /// ``` #[stable(feature = "assoc_char_funcs", since = "1.52.0")] + #[must_use] #[inline] pub fn from_u32(i: u32) -> Option { super::convert::from_u32(i) @@ -177,6 +178,7 @@ impl char { /// assert_eq!('❤', c); /// ``` #[stable(feature = "assoc_char_funcs", since = "1.52.0")] + #[must_use] #[inline] pub unsafe fn from_u32_unchecked(i: u32) -> char { // SAFETY: the safety contract must be upheld by the caller. @@ -230,9 +232,10 @@ impl char { /// use std::char; /// /// // this panics - /// char::from_digit(1, 37); + /// let _c = char::from_digit(1, 37); /// ``` #[stable(feature = "assoc_char_funcs", since = "1.52.0")] + #[must_use] #[inline] pub fn from_digit(num: u32, radix: u32) -> Option { super::convert::from_digit(num, radix) diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs index c47a2e8b05c4b..fd82be33d1abd 100644 --- a/library/core/src/num/f32.rs +++ b/library/core/src/num/f32.rs @@ -786,6 +786,7 @@ impl f32 { /// ``` #[stable(feature = "float_bits_conv", since = "1.20.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_bits(v: u32) -> Self { // SAFETY: `u32` is a plain old datatype so we can always transmute from it @@ -864,6 +865,7 @@ impl f32 { /// ``` #[stable(feature = "float_to_from_bytes", since = "1.40.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_be_bytes(bytes: [u8; 4]) -> Self { Self::from_bits(u32::from_be_bytes(bytes)) @@ -879,6 +881,7 @@ impl f32 { /// ``` #[stable(feature = "float_to_from_bytes", since = "1.40.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_le_bytes(bytes: [u8; 4]) -> Self { Self::from_bits(u32::from_le_bytes(bytes)) @@ -905,6 +908,7 @@ impl f32 { /// ``` #[stable(feature = "float_to_from_bytes", since = "1.40.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self { Self::from_bits(u32::from_ne_bytes(bytes)) diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs index cfcc08b9addeb..e7dec62c04ead 100644 --- a/library/core/src/num/f64.rs +++ b/library/core/src/num/f64.rs @@ -800,6 +800,7 @@ impl f64 { /// ``` #[stable(feature = "float_bits_conv", since = "1.20.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_bits(v: u64) -> Self { // SAFETY: `u64` is a plain old datatype so we can always transmute from it @@ -878,6 +879,7 @@ impl f64 { /// ``` #[stable(feature = "float_to_from_bytes", since = "1.40.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_be_bytes(bytes: [u8; 8]) -> Self { Self::from_bits(u64::from_be_bytes(bytes)) @@ -893,6 +895,7 @@ impl f64 { /// ``` #[stable(feature = "float_to_from_bytes", since = "1.40.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_le_bytes(bytes: [u8; 8]) -> Self { Self::from_bits(u64::from_le_bytes(bytes)) @@ -919,6 +922,7 @@ impl f64 { /// ``` #[stable(feature = "float_to_from_bytes", since = "1.40.0")] #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")] + #[must_use] #[inline] pub const fn from_ne_bytes(bytes: [u8; 8]) -> Self { Self::from_bits(u64::from_ne_bytes(bytes)) diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs index 12dda61400f2a..7ef2d5c40034d 100644 --- a/library/core/src/num/int_macros.rs +++ b/library/core/src/num/int_macros.rs @@ -282,6 +282,7 @@ macro_rules! int_impl { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] + #[must_use] #[inline] pub const fn from_be(x: Self) -> Self { #[cfg(target_endian = "big")] @@ -313,6 +314,7 @@ macro_rules! int_impl { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] + #[must_use] #[inline] pub const fn from_le(x: Self) -> Self { #[cfg(target_endian = "little")] @@ -2620,6 +2622,7 @@ macro_rules! int_impl { /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] #[inline] pub const fn from_be_bytes(bytes: [u8; mem::size_of::()]) -> Self { Self::from_be(Self::from_ne_bytes(bytes)) @@ -2650,6 +2653,7 @@ macro_rules! int_impl { /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] #[inline] pub const fn from_le_bytes(bytes: [u8; mem::size_of::()]) -> Self { Self::from_le(Self::from_ne_bytes(bytes)) @@ -2691,6 +2695,7 @@ macro_rules! int_impl { /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] // SAFETY: const sound because integers are plain old datatypes so we can always // transmute to them #[inline] diff --git a/library/core/src/num/saturating.rs b/library/core/src/num/saturating.rs index f6dd3603c4914..cf8cf79fe46e0 100644 --- a/library/core/src/num/saturating.rs +++ b/library/core/src/num/saturating.rs @@ -644,6 +644,7 @@ macro_rules! saturating_int_impl { /// } /// ``` #[inline] + #[must_use] #[unstable(feature = "saturating_int_impl", issue = "87920")] pub const fn from_be(x: Self) -> Self { Saturating(<$t>::from_be(x.0)) @@ -671,6 +672,7 @@ macro_rules! saturating_int_impl { /// } /// ``` #[inline] + #[must_use] #[unstable(feature = "saturating_int_impl", issue = "87920")] pub const fn from_le(x: Self) -> Self { Saturating(<$t>::from_le(x.0)) diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs index 25cd582bb67d7..eb03be2a62ae9 100644 --- a/library/core/src/num/uint_macros.rs +++ b/library/core/src/num/uint_macros.rs @@ -285,6 +285,7 @@ macro_rules! uint_impl { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", since = "1.32.0")] + #[must_use] #[inline(always)] pub const fn from_be(x: Self) -> Self { #[cfg(target_endian = "big")] @@ -317,6 +318,7 @@ macro_rules! uint_impl { /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", since = "1.32.0")] + #[must_use] #[inline(always)] pub const fn from_le(x: Self) -> Self { #[cfg(target_endian = "little")] @@ -2278,6 +2280,7 @@ macro_rules! uint_impl { /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] #[inline] pub const fn from_be_bytes(bytes: [u8; mem::size_of::()]) -> Self { Self::from_be(Self::from_ne_bytes(bytes)) @@ -2308,6 +2311,7 @@ macro_rules! uint_impl { /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] #[inline] pub const fn from_le_bytes(bytes: [u8; mem::size_of::()]) -> Self { Self::from_le(Self::from_ne_bytes(bytes)) @@ -2349,6 +2353,7 @@ macro_rules! uint_impl { /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] // SAFETY: const sound because integers are plain old datatypes so we can always // transmute to them #[inline] diff --git a/library/core/src/num/wrapping.rs b/library/core/src/num/wrapping.rs index b078cdf5479d7..cca83661b7ea6 100644 --- a/library/core/src/num/wrapping.rs +++ b/library/core/src/num/wrapping.rs @@ -638,6 +638,7 @@ macro_rules! wrapping_int_impl { /// } /// ``` #[inline] + #[must_use] #[unstable(feature = "wrapping_int_impl", issue = "32463")] pub const fn from_be(x: Self) -> Self { Wrapping(<$t>::from_be(x.0)) @@ -665,6 +666,7 @@ macro_rules! wrapping_int_impl { /// } /// ``` #[inline] + #[must_use] #[unstable(feature = "wrapping_int_impl", issue = "32463")] pub const fn from_le(x: Self) -> Self { Wrapping(<$t>::from_le(x.0)) diff --git a/library/core/src/str/converts.rs b/library/core/src/str/converts.rs index da6ef1b6678c6..ed9f49f159611 100644 --- a/library/core/src/str/converts.rs +++ b/library/core/src/str/converts.rs @@ -155,6 +155,7 @@ pub fn from_utf8_mut(v: &mut [u8]) -> Result<&mut str, Utf8Error> { /// assert_eq!("💖", sparkle_heart); /// ``` #[inline] +#[must_use] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_str_from_utf8_unchecked", since = "1.55.0")] pub const unsafe fn from_utf8_unchecked(v: &[u8]) -> &str { @@ -181,6 +182,7 @@ pub const unsafe fn from_utf8_unchecked(v: &[u8]) -> &str { /// assert_eq!("💖", heart); /// ``` #[inline] +#[must_use] #[stable(feature = "str_mut_extras", since = "1.20.0")] pub unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str { // SAFETY: the caller must guarantee that the bytes `v` diff --git a/library/core/src/str/lossy.rs b/library/core/src/str/lossy.rs index 720a35bbc8f2c..d3c9d21c3c756 100644 --- a/library/core/src/str/lossy.rs +++ b/library/core/src/str/lossy.rs @@ -12,10 +12,12 @@ pub struct Utf8Lossy { } impl Utf8Lossy { + #[must_use] pub fn from_str(s: &str) -> &Utf8Lossy { Utf8Lossy::from_bytes(s.as_bytes()) } + #[must_use] pub fn from_bytes(bytes: &[u8]) -> &Utf8Lossy { // SAFETY: Both use the same memory layout, and UTF-8 correctness isn't required. unsafe { mem::transmute(bytes) } diff --git a/library/core/src/task/wake.rs b/library/core/src/task/wake.rs index b775e022a54b4..e1bbdfaef8016 100644 --- a/library/core/src/task/wake.rs +++ b/library/core/src/task/wake.rs @@ -158,6 +158,7 @@ pub struct Context<'a> { impl<'a> Context<'a> { /// Create a new `Context` from a `&Waker`. #[stable(feature = "futures_api", since = "1.36.0")] + #[must_use] #[inline] pub fn from_waker(waker: &'a Waker) -> Self { Context { waker, _marker: PhantomData } @@ -251,6 +252,7 @@ impl Waker { /// in [`RawWaker`]'s and [`RawWakerVTable`]'s documentation is not upheld. /// Therefore this method is unsafe. #[inline] + #[must_use] #[stable(feature = "futures_api", since = "1.36.0")] pub unsafe fn from_raw(waker: RawWaker) -> Waker { Waker { waker } diff --git a/library/core/src/time.rs b/library/core/src/time.rs index d1533b8d67a6b..d57c959820d8d 100644 --- a/library/core/src/time.rs +++ b/library/core/src/time.rs @@ -203,6 +203,7 @@ impl Duration { /// assert_eq!(0, duration.subsec_nanos()); /// ``` #[stable(feature = "duration", since = "1.3.0")] + #[must_use] #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_secs(secs: u64) -> Duration { @@ -222,6 +223,7 @@ impl Duration { /// assert_eq!(569_000_000, duration.subsec_nanos()); /// ``` #[stable(feature = "duration", since = "1.3.0")] + #[must_use] #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_millis(millis: u64) -> Duration { @@ -244,6 +246,7 @@ impl Duration { /// assert_eq!(2000, duration.subsec_nanos()); /// ``` #[stable(feature = "duration_from_micros", since = "1.27.0")] + #[must_use] #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_micros(micros: u64) -> Duration { @@ -266,6 +269,7 @@ impl Duration { /// assert_eq!(123, duration.subsec_nanos()); /// ``` #[stable(feature = "duration_extras", since = "1.27.0")] + #[must_use] #[inline] #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")] pub const fn from_nanos(nanos: u64) -> Duration { @@ -692,6 +696,7 @@ impl Duration { /// assert_eq!(dur, Duration::new(2, 700_000_000)); /// ``` #[stable(feature = "duration_float", since = "1.38.0")] + #[must_use] #[inline] #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")] pub const fn from_secs_f64(secs: f64) -> Duration { @@ -753,6 +758,7 @@ impl Duration { /// assert_eq!(dur, Duration::new(2, 700_000_000)); /// ``` #[stable(feature = "duration_float", since = "1.38.0")] + #[must_use] #[inline] #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")] pub const fn from_secs_f32(secs: f32) -> Duration { diff --git a/library/std/src/ffi/c_str.rs b/library/std/src/ffi/c_str.rs index fe1f28f00c403..e290350993d73 100644 --- a/library/std/src/ffi/c_str.rs +++ b/library/std/src/ffi/c_str.rs @@ -425,6 +425,7 @@ impl CString { /// let c_string = CString::from_vec_unchecked(raw); /// } /// ``` + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub unsafe fn from_vec_unchecked(mut v: Vec) -> CString { v.reserve_exact(1); @@ -476,6 +477,7 @@ impl CString { /// let c_string = CString::from_raw(raw); /// } /// ``` + #[must_use = "call `drop(from_raw(ptr))` if you intend to drop the `CString`"] #[stable(feature = "cstr_memory", since = "1.4.0")] pub unsafe fn from_raw(ptr: *mut c_char) -> CString { // SAFETY: This is called with a pointer that was obtained from a call @@ -701,6 +703,7 @@ impl CString { /// unsafe { CString::from_vec_unchecked(b"abc".to_vec()) } /// ); /// ``` + #[must_use] #[unstable(feature = "cstring_from_vec_with_nul", issue = "73179")] pub unsafe fn from_vec_with_nul_unchecked(v: Vec) -> Self { Self { inner: v.into_boxed_slice() } @@ -1162,6 +1165,7 @@ impl CStr { /// } /// # } /// ``` + #[must_use] #[stable(feature = "rust1", since = "1.0.0")] pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr { // SAFETY: The caller has provided a pointer that points to a valid C @@ -1244,6 +1248,7 @@ impl CStr { /// } /// ``` #[inline] + #[must_use] #[stable(feature = "cstr_from_bytes", since = "1.10.0")] #[rustc_const_unstable(feature = "const_cstr_unchecked", issue = "none")] pub const unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr { diff --git a/library/std/src/io/error.rs b/library/std/src/io/error.rs index 51666c0a3c7f1..57b5c28430f1e 100644 --- a/library/std/src/io/error.rs +++ b/library/std/src/io/error.rs @@ -473,6 +473,7 @@ impl Error { /// # } /// ``` #[stable(feature = "rust1", since = "1.0.0")] + #[must_use] #[inline] pub fn from_raw_os_error(code: i32) -> Error { Error { repr: Repr::Os(code) }