diff options
Diffstat (limited to 'src/libcore')
| -rw-r--r-- | src/libcore/iter/mod.rs | 5 | ||||
| -rw-r--r-- | src/libcore/lib.rs | 2 | ||||
| -rw-r--r-- | src/libcore/mem/manually_drop.rs | 2 | ||||
| -rw-r--r-- | src/libcore/num/mod.rs | 29 | ||||
| -rw-r--r-- | src/libcore/ptr/const_ptr.rs | 5 |
5 files changed, 26 insertions, 17 deletions
diff --git a/src/libcore/iter/mod.rs b/src/libcore/iter/mod.rs index 80294de714d..0d5af3986fb 100644 --- a/src/libcore/iter/mod.rs +++ b/src/libcore/iter/mod.rs @@ -216,6 +216,11 @@ //! Common iterator adapters include [`map`], [`take`], and [`filter`]. //! For more, see their documentation. //! +//! If an iterator adapter panics, the iterator will be in an unspecified (but +//! memory safe) state. This state is also not guaranteed to stay the same +//! across versions of Rust, so you should avoid relying on the exact values +//! returned by an iterator which panicked. +//! //! [`map`]: trait.Iterator.html#method.map //! [`take`]: trait.Iterator.html#method.take //! [`filter`]: trait.Iterator.html#method.filter diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs index 7d11dd2800f..590f4e46c1d 100644 --- a/src/libcore/lib.rs +++ b/src/libcore/lib.rs @@ -71,6 +71,8 @@ #![feature(cfg_target_has_atomic)] #![feature(concat_idents)] #![feature(const_fn)] +#![feature(const_if_match)] +#![feature(const_panic)] #![feature(const_fn_union)] #![feature(const_generics)] #![feature(const_ptr_offset_from)] diff --git a/src/libcore/mem/manually_drop.rs b/src/libcore/mem/manually_drop.rs index af4635f89f6..36064488eb2 100644 --- a/src/libcore/mem/manually_drop.rs +++ b/src/libcore/mem/manually_drop.rs @@ -121,7 +121,7 @@ impl<T: ?Sized> ManuallyDrop<T> { /// This function runs the destructor of the contained value and thus the wrapped value /// now represents uninitialized data. It is up to the user of this method to ensure the /// uninitialized data is not actually used. - /// In particular, this function can only be called called at most once + /// In particular, this function can only be called at most once /// for a given instance of `ManuallyDrop<T>`. /// /// [`ManuallyDrop::into_inner`]: #method.into_inner diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs index 8a32479b2ff..14540394cab 100644 --- a/src/libcore/num/mod.rs +++ b/src/libcore/num/mod.rs @@ -1416,18 +1416,14 @@ $EndFeature, " ```"), #[stable(feature = "no_panic_abs", since = "1.13.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[allow_internal_unstable(const_if_match)] #[inline] pub const fn wrapping_abs(self) -> Self { - // sign is -1 (all ones) for negative numbers, 0 otherwise. - let sign = self >> ($BITS - 1); - // For positive self, sign == 0 so the expression is simply - // (self ^ 0).wrapping_sub(0) == self == abs(self). - // - // For negative self, self ^ sign == self ^ all_ones. - // But all_ones ^ self == all_ones - self == -1 - self. - // So for negative numbers, (self ^ sign).wrapping_sub(sign) is - // (-1 - self).wrapping_sub(-1) == -self == abs(self). - (self ^ sign).wrapping_sub(sign) + if self.is_negative() { + self.wrapping_neg() + } else { + self + } } } @@ -1713,8 +1709,13 @@ assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($Self #[inline] #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[allow_internal_unstable(const_if_match)] pub const fn overflowing_neg(self) -> (Self, bool) { - ((!self).wrapping_add(1), self == Self::min_value()) + if self == Self::min_value() { + (Self::min_value(), true) + } else { + (-self, false) + } } } @@ -2041,7 +2042,11 @@ $EndFeature, " #[rustc_const_unstable(feature = "const_int_sign", issue = "53718")] #[inline] pub const fn signum(self) -> Self { - (self > 0) as Self - (self < 0) as Self + match self { + n if n > 0 => 1, + 0 => 0, + _ => -1, + } } } diff --git a/src/libcore/ptr/const_ptr.rs b/src/libcore/ptr/const_ptr.rs index e5297a0c1e0..fc3c02e1f06 100644 --- a/src/libcore/ptr/const_ptr.rs +++ b/src/libcore/ptr/const_ptr.rs @@ -288,10 +288,7 @@ impl<T: ?Sized> *const T { T: Sized, { let pointee_size = mem::size_of::<T>(); - let ok = 0 < pointee_size && pointee_size <= isize::max_value() as usize; - // assert that the pointee size is valid in a const eval compatible way - // FIXME: do this with a real assert at some point - [()][(!ok) as usize]; + assert!(0 < pointee_size && pointee_size <= isize::max_value() as usize); intrinsics::ptr_offset_from(self, origin) } |