From d7b2fd4213971edd09ed72f9a6541a036d016666 Mon Sep 17 00:00:00 2001 From: Geoffry Song Date: Wed, 21 Aug 2024 14:37:39 -0700 Subject: Clean up cfg-gating of ProcessPrng extern --- library/std/src/sys/pal/windows/c.rs | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) (limited to 'library/std/src') diff --git a/library/std/src/sys/pal/windows/c.rs b/library/std/src/sys/pal/windows/c.rs index 2f5d75dc4bc..8900410cf60 100644 --- a/library/std/src/sys/pal/windows/c.rs +++ b/library/std/src/sys/pal/windows/c.rs @@ -109,19 +109,22 @@ if #[cfg(not(target_vendor = "uwp"))] { } // Use raw-dylib to import ProcessPrng as we can't rely on there being an import library. -cfg_if::cfg_if! { -if #[cfg(not(target_vendor = "win7"))] { - #[cfg(target_arch = "x86")] - #[link(name = "bcryptprimitives", kind = "raw-dylib", import_name_type = "undecorated")] - extern "system" { - pub fn ProcessPrng(pbdata: *mut u8, cbdata: usize) -> BOOL; - } - #[cfg(not(target_arch = "x86"))] - #[link(name = "bcryptprimitives", kind = "raw-dylib")] - extern "system" { - pub fn ProcessPrng(pbdata: *mut u8, cbdata: usize) -> BOOL; - } -}} +#[cfg(not(target_vendor = "win7"))] +#[cfg_attr( + target_arch = "x86", + link( + name = "bcryptprimitives", + kind = "raw-dylib", + import_name_type = "undecorated" + ) +)] +#[cfg_attr( + not(target_arch = "x86"), + link(name = "bcryptprimitives", kind = "raw-dylib") +)] +extern "system" { + pub fn ProcessPrng(pbdata: *mut u8, cbdata: usize) -> BOOL; +} // Functions that aren't available on every version of Windows that we support, // but we still use them and just provide some form of a fallback implementation. -- cgit 1.4.1-3-g733a5 From 40481fc70a8626f9e58242b0fb673d90ade2f084 Mon Sep 17 00:00:00 2001 From: Geoffry Song Date: Wed, 21 Aug 2024 15:34:51 -0700 Subject: format --- library/std/src/sys/pal/windows/c.rs | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) (limited to 'library/std/src') diff --git a/library/std/src/sys/pal/windows/c.rs b/library/std/src/sys/pal/windows/c.rs index 8900410cf60..b888eb7d95c 100644 --- a/library/std/src/sys/pal/windows/c.rs +++ b/library/std/src/sys/pal/windows/c.rs @@ -112,16 +112,9 @@ if #[cfg(not(target_vendor = "uwp"))] { #[cfg(not(target_vendor = "win7"))] #[cfg_attr( target_arch = "x86", - link( - name = "bcryptprimitives", - kind = "raw-dylib", - import_name_type = "undecorated" - ) -)] -#[cfg_attr( - not(target_arch = "x86"), - link(name = "bcryptprimitives", kind = "raw-dylib") + link(name = "bcryptprimitives", kind = "raw-dylib", import_name_type = "undecorated") )] +#[cfg_attr(not(target_arch = "x86"), link(name = "bcryptprimitives", kind = "raw-dylib"))] extern "system" { pub fn ProcessPrng(pbdata: *mut u8, cbdata: usize) -> BOOL; } -- cgit 1.4.1-3-g733a5 From 169b2f0e6dfd534a21372e0c9f1f4357149f112a Mon Sep 17 00:00:00 2001 From: Jubilee Young Date: Wed, 21 Aug 2024 22:22:18 -0700 Subject: library: Stabilize new_uninit for Box, Rc, and Arc A partial stabilization that only affects: - AllocType::new_uninit - AllocType::assume_init - AllocType<[T]>::new_uninit_slice - AllocType<[T]>::assume_init where "AllocType" is Box, Rc, or Arc --- library/alloc/src/boxed.rs | 43 ++++++++++++++++--------------------------- library/alloc/src/lib.rs | 1 - library/alloc/src/rc.rs | 26 ++++++++------------------ library/alloc/src/sync.rs | 26 ++++++++------------------ library/alloc/tests/lib.rs | 1 - library/proc_macro/src/lib.rs | 1 - library/std/src/lib.rs | 1 - 7 files changed, 32 insertions(+), 67 deletions(-) (limited to 'library/std/src') diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs index caaf37f0465..38b1766c174 100644 --- a/library/alloc/src/boxed.rs +++ b/library/alloc/src/boxed.rs @@ -262,8 +262,6 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(new_uninit)] - /// /// let mut five = Box::::new_uninit(); /// /// let five = unsafe { @@ -276,7 +274,7 @@ impl Box { /// assert_eq!(*five, 5) /// ``` #[cfg(not(no_global_oom_handling))] - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use] #[inline] pub fn new_uninit() -> Box> { @@ -292,7 +290,6 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(new_zeroed_alloc)] /// /// let zero = Box::::new_zeroed(); @@ -350,7 +347,7 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// let mut five = Box::::try_new_uninit()?; /// @@ -380,7 +377,7 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// let zero = Box::::try_new_zeroed()?; /// let zero = unsafe { zero.assume_init() }; @@ -460,7 +457,7 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -498,7 +495,7 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -538,7 +535,7 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -576,7 +573,7 @@ impl Box { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -654,8 +651,6 @@ impl Box<[T]> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] - /// /// let mut values = Box::<[u32]>::new_uninit_slice(3); /// /// let values = unsafe { @@ -670,7 +665,7 @@ impl Box<[T]> { /// assert_eq!(*values, [1, 2, 3]) /// ``` #[cfg(not(no_global_oom_handling))] - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use] pub fn new_uninit_slice(len: usize) -> Box<[mem::MaybeUninit]> { unsafe { RawVec::with_capacity(len).into_box(len) } @@ -686,7 +681,6 @@ impl Box<[T]> { /// /// ``` /// #![feature(new_zeroed_alloc)] - /// #![feature(new_uninit)] /// /// let values = Box::<[u32]>::new_zeroed_slice(3); /// let values = unsafe { values.assume_init() }; @@ -708,7 +702,7 @@ impl Box<[T]> { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// let mut values = Box::<[u32]>::try_new_uninit_slice(3)?; /// let values = unsafe { @@ -746,7 +740,7 @@ impl Box<[T]> { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// let values = Box::<[u32]>::try_new_zeroed_slice(3)?; /// let values = unsafe { values.assume_init() }; @@ -778,7 +772,7 @@ impl Box<[T], A> { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -812,7 +806,7 @@ impl Box<[T], A> { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -837,7 +831,7 @@ impl Box<[T], A> { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -880,7 +874,7 @@ impl Box<[T], A> { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::alloc::System; /// @@ -927,8 +921,6 @@ impl Box, A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] - /// /// let mut five = Box::::new_uninit(); /// /// let five: Box = unsafe { @@ -940,7 +932,7 @@ impl Box, A> { /// /// assert_eq!(*five, 5) /// ``` - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[inline] pub unsafe fn assume_init(self) -> Box { let (raw, alloc) = Box::into_raw_with_allocator(self); @@ -958,7 +950,6 @@ impl Box, A> { /// /// ``` /// #![feature(box_uninit_write)] - /// #![feature(new_uninit)] /// /// let big_box = Box::<[usize; 1024]>::new_uninit(); /// @@ -1001,8 +992,6 @@ impl Box<[mem::MaybeUninit], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] - /// /// let mut values = Box::<[u32]>::new_uninit_slice(3); /// /// let values = unsafe { @@ -1016,7 +1005,7 @@ impl Box<[mem::MaybeUninit], A> { /// /// assert_eq!(*values, [1, 2, 3]) /// ``` - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[inline] pub unsafe fn assume_init(self) -> Box<[T], A> { let (raw, alloc) = Box::into_raw_with_allocator(self); diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs index 5e4b08df6cb..c459a8da820 100644 --- a/library/alloc/src/lib.rs +++ b/library/alloc/src/lib.rs @@ -93,7 +93,6 @@ // tidy-alphabetical-start #![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))] #![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))] -#![cfg_attr(test, feature(new_uninit))] #![feature(alloc_layout_extra)] #![feature(allocator_api)] #![feature(array_chunks)] diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs index f153aa6d3be..1b31a78394e 100644 --- a/library/alloc/src/rc.rs +++ b/library/alloc/src/rc.rs @@ -503,7 +503,6 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::rc::Rc; @@ -518,7 +517,7 @@ impl Rc { /// assert_eq!(*five, 5) /// ``` #[cfg(not(no_global_oom_handling))] - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use] pub fn new_uninit() -> Rc> { unsafe { @@ -540,7 +539,6 @@ impl Rc { /// /// ``` /// #![feature(new_zeroed_alloc)] - /// #![feature(new_uninit)] /// /// use std::rc::Rc; /// @@ -594,7 +592,7 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// #![feature(get_mut_unchecked)] /// /// use std::rc::Rc; @@ -630,7 +628,7 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::rc::Rc; /// @@ -692,7 +690,6 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// #![feature(allocator_api)] /// @@ -736,7 +733,6 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(allocator_api)] /// /// use std::rc::Rc; @@ -799,7 +795,7 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// #![feature(get_mut_unchecked)] /// /// use std::rc::Rc; @@ -843,7 +839,7 @@ impl Rc { /// # Examples /// /// ``` - /// #![feature(allocator_api, new_uninit)] + /// #![feature(allocator_api)] /// /// use std::rc::Rc; /// use std::alloc::System; @@ -967,7 +963,6 @@ impl Rc<[T]> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::rc::Rc; @@ -985,7 +980,7 @@ impl Rc<[T]> { /// assert_eq!(*values, [1, 2, 3]) /// ``` #[cfg(not(no_global_oom_handling))] - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use] pub fn new_uninit_slice(len: usize) -> Rc<[mem::MaybeUninit]> { unsafe { Rc::from_ptr(Rc::allocate_for_slice(len)) } @@ -1000,7 +995,6 @@ impl Rc<[T]> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(new_zeroed_alloc)] /// /// use std::rc::Rc; @@ -1035,7 +1029,6 @@ impl Rc<[T], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// #![feature(allocator_api)] /// @@ -1072,7 +1065,6 @@ impl Rc<[T], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(allocator_api)] /// /// use std::rc::Rc; @@ -1122,7 +1114,6 @@ impl Rc, A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::rc::Rc; @@ -1136,7 +1127,7 @@ impl Rc, A> { /// /// assert_eq!(*five, 5) /// ``` - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[inline] pub unsafe fn assume_init(self) -> Rc { let (ptr, alloc) = Rc::into_inner_with_allocator(self); @@ -1160,7 +1151,6 @@ impl Rc<[mem::MaybeUninit], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::rc::Rc; @@ -1177,7 +1167,7 @@ impl Rc<[mem::MaybeUninit], A> { /// /// assert_eq!(*values, [1, 2, 3]) /// ``` - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[inline] pub unsafe fn assume_init(self) -> Rc<[T], A> { let (ptr, alloc) = Rc::into_inner_with_allocator(self); diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs index 4a3522f1a64..aac768eb053 100644 --- a/library/alloc/src/sync.rs +++ b/library/alloc/src/sync.rs @@ -505,7 +505,6 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::sync::Arc; @@ -521,7 +520,7 @@ impl Arc { /// ``` #[cfg(not(no_global_oom_handling))] #[inline] - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use] pub fn new_uninit() -> Arc> { unsafe { @@ -543,7 +542,6 @@ impl Arc { /// /// ``` /// #![feature(new_zeroed_alloc)] - /// #![feature(new_uninit)] /// /// use std::sync::Arc; /// @@ -614,7 +612,7 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit, allocator_api)] + /// #![feature(allocator_api)] /// #![feature(get_mut_unchecked)] /// /// use std::sync::Arc; @@ -650,7 +648,7 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit, allocator_api)] + /// #![feature( allocator_api)] /// /// use std::sync::Arc; /// @@ -711,7 +709,6 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// #![feature(allocator_api)] /// @@ -755,7 +752,6 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(allocator_api)] /// /// use std::sync::Arc; @@ -845,7 +841,7 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit, allocator_api)] + /// #![feature(allocator_api)] /// #![feature(get_mut_unchecked)] /// /// use std::sync::Arc; @@ -889,7 +885,7 @@ impl Arc { /// # Examples /// /// ``` - /// #![feature(new_uninit, allocator_api)] + /// #![feature(allocator_api)] /// /// use std::sync::Arc; /// use std::alloc::System; @@ -1101,7 +1097,6 @@ impl Arc<[T]> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::sync::Arc; @@ -1120,7 +1115,7 @@ impl Arc<[T]> { /// ``` #[cfg(not(no_global_oom_handling))] #[inline] - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use] pub fn new_uninit_slice(len: usize) -> Arc<[mem::MaybeUninit]> { unsafe { Arc::from_ptr(Arc::allocate_for_slice(len)) } @@ -1136,7 +1131,6 @@ impl Arc<[T]> { /// /// ``` /// #![feature(new_zeroed_alloc)] - /// #![feature(new_uninit)] /// /// use std::sync::Arc; /// @@ -1172,7 +1166,6 @@ impl Arc<[T], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// #![feature(allocator_api)] /// @@ -1208,7 +1201,6 @@ impl Arc<[T], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(allocator_api)] /// /// use std::sync::Arc; @@ -1257,7 +1249,6 @@ impl Arc, A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::sync::Arc; @@ -1271,7 +1262,7 @@ impl Arc, A> { /// /// assert_eq!(*five, 5) /// ``` - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use = "`self` will be dropped if the result is not used"] #[inline] pub unsafe fn assume_init(self) -> Arc { @@ -1296,7 +1287,6 @@ impl Arc<[mem::MaybeUninit], A> { /// # Examples /// /// ``` - /// #![feature(new_uninit)] /// #![feature(get_mut_unchecked)] /// /// use std::sync::Arc; @@ -1313,7 +1303,7 @@ impl Arc<[mem::MaybeUninit], A> { /// /// assert_eq!(*values, [1, 2, 3]) /// ``` - #[unstable(feature = "new_uninit", issue = "63291")] + #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")] #[must_use = "`self` will be dropped if the result is not used"] #[inline] pub unsafe fn assume_init(self) -> Arc<[T], A> { diff --git a/library/alloc/tests/lib.rs b/library/alloc/tests/lib.rs index 3d4add6fae4..c5c6a122cfe 100644 --- a/library/alloc/tests/lib.rs +++ b/library/alloc/tests/lib.rs @@ -15,7 +15,6 @@ #![feature(exact_size_is_empty)] #![feature(linked_list_cursors)] #![feature(map_try_insert)] -#![feature(new_uninit)] #![feature(pattern)] #![feature(trusted_len)] #![feature(try_reserve_kind)] diff --git a/library/proc_macro/src/lib.rs b/library/proc_macro/src/lib.rs index c271ac18706..72b53c60f74 100644 --- a/library/proc_macro/src/lib.rs +++ b/library/proc_macro/src/lib.rs @@ -28,7 +28,6 @@ #![feature(decl_macro)] #![feature(maybe_uninit_write_slice)] #![feature(negative_impls)] -#![feature(new_uninit)] #![feature(panic_can_unwind)] #![feature(restricted_std)] #![feature(rustc_attrs)] diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs index f65e9bc8d8b..bea8eda2619 100644 --- a/library/std/src/lib.rs +++ b/library/std/src/lib.rs @@ -362,7 +362,6 @@ #![feature(allocator_api)] #![feature(get_mut_unchecked)] #![feature(map_try_insert)] -#![feature(new_uninit)] #![feature(new_zeroed_alloc)] #![feature(slice_concat_trait)] #![feature(thin_box)] -- cgit 1.4.1-3-g733a5 From 0589dc75d314152de3ddf095ff2fc774c4a2d9c1 Mon Sep 17 00:00:00 2001 From: Ralf Jung Date: Wed, 28 Aug 2024 12:06:28 +0200 Subject: copysign with sign being a NaN is non-portable --- library/std/src/f128.rs | 11 ++++++++--- library/std/src/f16.rs | 11 ++++++++--- library/std/src/f32.rs | 11 ++++++++--- library/std/src/f64.rs | 11 ++++++++--- 4 files changed, 32 insertions(+), 12 deletions(-) (limited to 'library/std/src') diff --git a/library/std/src/f128.rs b/library/std/src/f128.rs index 506d708d0d2..b436fe9929c 100644 --- a/library/std/src/f128.rs +++ b/library/std/src/f128.rs @@ -250,9 +250,14 @@ impl f128 { /// /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`. /// If `self` is a NaN, then a NaN with the same payload as `self` and the sign bit of `sign` is - /// returned. Note, however, that conserving the sign bit on NaN across arithmetical operations - /// is not generally guaranteed. See [specification of NaN bit - /// patterns](primitive@f32#nan-bit-patterns) for more info. + /// returned. + /// + /// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note + /// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust + /// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the + /// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable + /// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more + /// info. /// /// # Examples /// diff --git a/library/std/src/f16.rs b/library/std/src/f16.rs index 033a3d45009..b2cd5fae9d0 100644 --- a/library/std/src/f16.rs +++ b/library/std/src/f16.rs @@ -249,9 +249,14 @@ impl f16 { /// /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`. /// If `self` is a NaN, then a NaN with the same payload as `self` and the sign bit of `sign` is - /// returned. Note, however, that conserving the sign bit on NaN across arithmetical operations - /// is not generally guaranteed. See [specification of NaN bit - /// patterns](primitive@f32#nan-bit-patterns) for more info. + /// returned. + /// + /// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note + /// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust + /// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the + /// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable + /// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more + /// info. /// /// # Examples /// diff --git a/library/std/src/f32.rs b/library/std/src/f32.rs index 35c2a77b533..cafbe9761da 100644 --- a/library/std/src/f32.rs +++ b/library/std/src/f32.rs @@ -228,9 +228,14 @@ impl f32 { /// /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`. /// If `self` is a NaN, then a NaN with the same payload as `self` and the sign bit of `sign` is - /// returned. Note, however, that conserving the sign bit on NaN across arithmetical operations - /// is not generally guaranteed. See [specification of NaN bit - /// patterns](primitive@f32#nan-bit-patterns) for more info. + /// returned. + /// + /// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note + /// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust + /// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the + /// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable + /// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more + /// info. /// /// # Examples /// diff --git a/library/std/src/f64.rs b/library/std/src/f64.rs index c177f74a97e..fba283e3a44 100644 --- a/library/std/src/f64.rs +++ b/library/std/src/f64.rs @@ -228,9 +228,14 @@ impl f64 { /// /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`. /// If `self` is a NaN, then a NaN with the same payload as `self` and the sign bit of `sign` is - /// returned. Note, however, that conserving the sign bit on NaN across arithmetical operations - /// is not generally guaranteed. See [specification of NaN bit - /// patterns](primitive@f32#nan-bit-patterns) for more info. + /// returned. + /// + /// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note + /// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust + /// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the + /// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable + /// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more + /// info. /// /// # Examples /// -- cgit 1.4.1-3-g733a5